Editor's Note: Adobe Acrobat and PDF officially turned 10 years of age this past Sunday, June 15 -- Father's Day, quite appropriately. John Warnock, Adobe Systems co-founder, chairman and former CEO, is widely and rightly credited as being the 'father of Acrobat and PDF,' an enlightened vision he initially espoused in his now-famous "Camelot" report (at right). In the years since the technology was publicly launched in mid-1993, the software and format have had a number of other fathers, mentors and guiding spirits who have continued to nurture and build on the original concept. One of those is Bob Wulff, who was lured by Warnock in a hallway encounter in 1990 to lend some technical assistance to the fledgling project 'for a couple weeks.' More than a dozen years later, Wulff has become not only one of the firm believers, but also one of the main keepers of the faith. We talked with him early this week to discuss the technological milestone and his role in it.
PLANET PDF: Bob, we realize you're probably still in recovery mode so soon after the release of the Acrobat 6.0 product family late last month, so we appreciate you making time to talk with Planet PDF again. So first, Congratulations to you and the Engineering team for what most seem to agree is the best version of Acrobat yet. We'd like to hear a little about the specifics of that process, and how it compared to working on previous versions. Since you're one of a very select group at Adobe that's been part of this from the very early days, we know you've got a unique insight. Before we get to that, we'd like to learn a little about you and your background, and then we'll move into your role, your Acrobat history and the current release.
Tell us a little about any relevant pre-Adobe education, experience and work history.
BOB WULFF, ADOBE SYSTEMS: "Education-wise I got a Masters degree in Computer Science from Stanford University in the late 70s. Then I went off and did the standard Silicon Valley thing -- went to work for a startup called GRiD Systems. They were building portable computers long before the IBM PC came out. I worked in their software group in various engineering and management roles. And when that startup was acquired due to poor revenues, I went to another little startup. I was young and had lots of energy back then! This was a company called Mirus, which was building a desktop machine that could expose 35mm slides, kind of like a desktop printer, but it printed to film instead of paper. That really got me into computer graphics because I was working on printer drivers at that time. That was probably around 1986 or 87' long before Adobe Type Manager came out. There really weren't readily available fonts, so we had to do our own font technology. We were doing full 24-bit color imaging back in Windows 2; trying to do that in 640 kb of RAM was very interesting and challenging. I learned a lot about high-resolution color graphics in small memory spaces, which was a lot of fun.
When *that* company went out of business, I started to look around for a company that *wasn't* going to go out of business. By then I had a few kids, a house and a mortgage and all that. I kept seeing this company 'Adobe' -- their quarterly earnings report would come out and I could see that they were a profitable software company. I called a friend who I knew worked here, he got me an interview and that's how I ended up at Adobe in December 1989, right after the earthquake we had out here."
"I think Acrobat is a great example of where somebody had a vision -- born in about 1989 or 90 -- and a team of very hard-working people who were put together to provide the perspiration for that inspiration. It took longer for it to become a market success than maybe some other products. But the vision was always true. And the people that we added to the product continue to add visionary ideas even beyond John Warnock's original ideas, and have kept the mission alive." Bob Wulff, Adobe Systems, VP Acrobat Engineering
PLANET PDF: For what role, job or skills were you initially hired by Adobe?
WULFF: "I was hired to help get Adobe Illustrator to be a more portable code base and in particular, to port it to the NeXT machine. I worked on that for a couple of months until they realized that I was one of the few token Windows programmers they had at Adobe at that time. Everyone was a Mac programmer. And Adobe was way behind on Windows development, when Windows 3 was on the horizon. So I worked on Adobe Type Manager for Windows, version 1 and then worked on a string of Windows programs -- Adobe Illustrator, I put together the team for Photoshop for Windows, and Premiere for Windows. So I kind of got on the Windows team-building track for a couple years."
PLANET PDF: I read in "The Adobe Story" book by Pamela Pfiffner that your segue to the early development efforts that eventually led to Acrobat 1.0 and PDF came about because of a hallway encounter with former CEO John Warnock, who said he needed your help 'for a couple of weeks.'
Since we've just passed the 10-year anniversary of the June 15, 1993 public release of Acrobat and PDF, it appears that it was either a good fit or destiny, or perhaps both.
WULFF: It was a simple as that. It was the summer of 1990 and John had this idea for "Camelot" or "Carousel," as we were calling it in those days. He was looking for a Windows programmer to produce a demo for IBM, and he bumped into me. That's where it really started. The first year or so of what became Acrobat were really a series of demos -- to IBM and to a bunch of different companies. It didn't really have a formal organization or team. We cranked out a bunch of demos -- took a lot of code from the Illustrator code base and we were certainly having a lot of fun and generating a lot of enthusiasm for the whole concept. But we didn't really have an organized team or schedule or anything at the very beginning. It was probably in late 1991 when they brought in essentially a General Manager and we gathered probably 30 or 40 employees from different parts of the company and just took them off to the side and said 'You're the 'Carousel'' team and you're going to go off and build this product.
I think that was one of the smartest things we did -- it was really important to keep the team separate from the rest of Adobe because we were really working on something that, in many ways, required us to be left alone.
At that time -- around 1991 -- Adobe was a very thriving business with PostScript, fonts, and Illustrator and Photoshop was just starting to take off. There really was a lot going on. So they took us and separated us out, and let us do our thing. Of course there was a lot of interest from the entire company as to what we were doing and we received lots and lots of help from all different parts of the company.
PLANET PDF: Early this week we passed the now-historic June 15 date marking a decade since Acrobat and PDF were officially released by Adobe in 1993. But clearly it existed internally for some time prior, and Warnock was discussing the concept at select industry events at least a couple years in advance of the rollout. What are some of the most lasting impressions from -- or what are your keenest memories of -- getting involved with the "Carousel" project? What appealed to you about getting involved in building something from scratch?
WULFF: "It's always fun to work on a 1.0 version of something, and I'd done that at GRiD. To be able to do that again -- it's a very exciting thing to do. You kind of start with a blank slate, and in the software world, that's not something you get to do very often.
In the early years we were essentially inventing something -- I don't want to say that we were making it up as we were going along, but there was a lot of that! There was a lot of creative thinking and imagination. The reason we really needed to be separated was that there was no way we could implement all of the ideas that people were coming up with. People were coming up with great ideas from all parts of the company. I spent a lot of time saying 'No' because there was simply no way we could absorb all of these ideas, investigate them, let alone implement them and ever get a product out the door. What you saw in Acrobat 1.0 was a very small subset of the ideas that we were talking about in those days.
There are always new ideas coming along, but certainly a lot of the ideas that you've seen in later versions of Acrobat were ones that we had from the very beginning. The 'Search' feature is a great example. We had actually a very powerful 'Search' feature in Acrobat 2 -- the first time we added 'Search' and Catalog -- but we left it alone for a number of years. Then in Acrobat 6 we finally had enough time and energy to add a lot of the features to 'Search' that we've been thinking ever since Acrobat 1 and 2."
PLANET PDF: Tell us a little about what your current role as Vice President for Acrobat Engineering entails now.
WULFF: "I run the Engineering and Quality Assurance (QA) Group for the Acrobat/Desktop series of products. And that also includes Program Management and Release Engineering. Our goal is to build the Acrobat desktop family of products -- and it's becoming a larger family, it seems, with every release -- and work with the rest of the company as we integrate the technology from other parts of Adobe, and work with Marketing to make sure that we're not only building a reliable product, but that we're also building the *right* product for our customers and building it on a reasonable schedule. My job is really to make sure that we have the right teams in place to accomplish those goals."
PLANET PDF: How many 'teams' are involved and what does each do?
WULFF: "We have the various Engineering teams that work on the different features or plug-ins of Acrobat: a Security team, a Collaboration team, a team that worries about Prepress issues, a team that worries about Enterprise issues -- we basically have separate teams, some of them small and some of them large -- for all of the different parts of Acrobat. Then we have a QA team that has to test all the wonderful features that the engineers have put in, and that is quite a challenge. As you know, Acrobat has become a very large product with a large feature set over the years and so testing it on all of the different platforms, different languages, all the different printers and browsers is a huge and complicated process. We have a Release Engineering team that has to build the whole product and we build it every night, sometimes twice a day even -- we build every version of Acrobat -- Reader, Standard and Professional -- in all of the languages for all of the different operating systems. And then we run through a series of automated tests before we actually do the human testing. And then we have a set of Program Managers that keep us all organized."
PLANET PDF: Jim King noted in an interview we recently published that Acrobat and PDF have in a sense come full circle from Acrobat 1.0 to the latest release -- returning more to its initial purpose as an office tool. But as experienced users are well-aware, Acrobat is a multi-faceted application that can be used for a wide variety of purposes and as part of a wide-ranging number of solutions, from prepress to archiving to forms to document management, just to name a few. What are the main challenges from the Acrobat engineering perspective in developing and periodically updating such a multi-dimensional product, as opposed to a more narrowly focused product?
WULFF: "One of the challenges people have, especially when they're new to Acrobat, is trying to understand the surface area of the product. It is quite wide and horizontal, but it's also deep and has a couple of verticals. Acrobat is not one of those products for which you can come up with a good 'elevator pitch' because there's just too much going on. You have to adjust to that. So one of the things we have to do is make sure that we have experts -- on the Engineering, Marketing and QA side -- for all the different areas and all the different feature sets. We can't just focus on one thing. The analogy I make is 'What do people do with paper?' Well, they do *everything* with paper. So what are you going to do with electronic paper? Well, you're going to do a lot of things with electronic paper. So people just have to get used to that if they want to work on Acrobat. But that's our mission: to find interesting ways for people to use electronic paper and portable documents."
PLANET PDF: For the Engineering group, how have the challenges changed over the years and different versions of Acrobat?
WULFF: "In the early days, because we were inventing a new product category, there certainly was a lot more of coming up with ideas, but not being able to really test them in the market because people had no idea what Acrobat was all about, let alone trying to ask them about some new feature of Acrobat. We spent a number of years just explaining to people what this whole concept and category was.
From an Engineering point of view, we had people working on features and we used our best judgment to try to guess at some level which features should be in, or not in, a release. As Acrobat has become more successful over the years, we can do a lot more market research to figure out what sort of features and markets we should be going after. That's changed the engineering quite a bit -- it's just a lot more predictable as to whether a certain feature should be in our out. We've always worked closely with Marketing, but I think now we just have a lot more market data to go by. That doesn't mean that we don't still add features that customers are not asking for because there are always interesting ideas that customers haven't thought of yet. We're always trying to think of those and to make sure that each new release has its fair share of new and exciting ideas that can lead to new markets."
PLANET PDF: Jim King referred to the use of Acrobat and PDF internally for an extended period before they were launched in mid-1993. It sounds like you had your own pilot project running before most people outside Adobe ever heard about Acrobat, or thought much about how PDF could be used within an organization or corporation.
WULFF: "I think that's one of the best things about working at Adobe -- Adobe itself is a huge internal customer for the product. Not only to test new features, but when we get down to the final crunch or we're making releases, we make the release to the whole company and we have a process for the whole company to tell us about bugs, which they're not very shy about doing. It's just a great way to use your own product. Certainly most of the documents that are emailed around Adobe are PDFs. Most, if not all of the forms that people fill out in the course of their daily work, are PDF documents connected to our Forms Server. It's hard to find a place within Adobe where we're not using PDF to perform some job function. That gives us a great testbed for us to figure out which features are actually useful in a corporation. It also helps greatly on things like cross-platform testing, as we have many Windows, Mac and Unix machines, and now hand-held devices, too, that can also support Acrobat."
PLANET PDF: What is the actual process for the development of the various desktop products -- Acrobat and Reader -- and components (once separate products) -- Distiller, Catalog, etc -- in multiple languages and for numerous platforms, all developed more or less in tandem for a major new release?
WULFF: "One thing that we do is that we actually have one codebase for all of the flavors of Acrobat. By the time they pop out to the end user, they appear as different products. But they're all actually generated as much as possible off of the same codebase. That's the only way we can keep our sanity.
It is pretty complicated obviously, as we have the Reader, Standard and Pro and they have ever-increasing sets of features. We have to test the interaction between those, especially as you create a document with Pro and want to view it on a Reader product, potentially even from an earlier release of Acrobat, and making sure that all of the little details -- like all of the different security options, and the digital signatures, and all of the printing options -- making sure that they all work.
It's always our goal to share as much code as possible. That way when you fix a bug, it's fixed for all versions."
PLANET PDF: While we're on the theme of different products and versions, one of the areas of confusion we continue to hear a lot about from users has to do with whether you can have both Acrobat and Reader -- especially different versions, or even multiple versions, of each -- installed on the same computer. Do you have any recommendations, or is there any sort of Adobe policy or position, on that issue?
WULFF: "The position is that when you double-click a PDF file, we will launch the version of Acrobat that has the most features. It is possible to install Reader and Standard, or Reader and Pro; I think it's also possible to install different versions, but we discourage that in the installation process. The feeling is that if you have a pay-for product and double-click a PDF file, that's the version that should be running."
PLANET PDF: Like the rest of the Acrobat group, the engineering team has grown along with the product and its popularity. How large is the group today, and how is the product development process managed -- especially with the various development sites that Adobe now has outside of San Jose and some outside the United States? If I recall correctly, the Reader for the Palm OS was developed by Adobe India. What are the pros and cons of having a global engineering workflow?
WULFF: "I can't put a number on the group's current size, but it certainly has grown from the Acrobat 1.0 days. We also have, as you know, people at multiple sites around the world. I probably can't even name all of the sites -- there's India, Boston, Seattle, North Carolina, San Diego. San Luis Obispo, Minnesota, and of course our new team in Ottawa (formerly Accelio). That has provided a number of challenges. Certainly you have to get very good at using email and videoconferencing and telephone. We very much live and die with our bug database, which is how everyone communicates about bugs, and our source code control system -- everyone can check in and check out.
The great thing about it is that when we're going home at night and going to sleep in San Jose, we have teams around the world waking up to work on whatever issues need to be worked on. If you divide the product up into the right subsets, then you can have teams -- especially when you have teams of critical mass, like five or ten people -- then you can work on some very large features and they don't have to be in San Jose. They can really be anywhere. As long as you have good engineers and good managers -- which we do -- you can do that quite successfully."
PLANET PDF: Would all of the Adobe sites you mentioned get involved
in some aspect of Acrobat development during a major upgrade of the
WULFF: "They'd all have some part of it. But the other thing is that Adobe has a culture of using shared technology between the different engineering groups. So while the Acrobat team writes much of the code, if not the majority of the code for a release, we share a lot of technology from a lot of different groups. And those groups again are all over the world. We get a lot of leverage from these core or shared components because many Adobe products use them -- shared testing and shared development. And the reverse happens, too -- we actually write code for Acrobat that ends up in other products that people don't even realize comes from the Acrobat team. A big part of the PDF Library, for example, comes from the Acrobat team."
PLANET PDF: We joked in the beginning that you're still in recovery mode following the launch of Acrobat 6, but we realize that doesn't mean you've suddenly got nothing to do. What *is* the Acrobat Engineering team doing now? With a two-year product cycle for Acrobat, at what point do you typically begin working on the next full version?
WULFF: "At this point, most of them are going on vacation! I haven't taken mine yet -- somebody has to mind the store. I'll be taking mine later. So that's the first thing everyone does. We actually still have a little bit of work to do with all the different languages we have to finish -- they don't all come out quite the same day. It's takes a few weeks to get them all out. And then we really begin the process again. There's really a lot of ideas, as I said before, that we just didn't get around to implementing for Acrobat 6. We have no lack of ideas to draw from for the next release. So for some of our people, the next release actually begins before the previous release begins shipping.
The way the cycle actually works is that once the engineers have finished implementing their features and have fixed all of the bugs that the QA teams have found, they're no longer working on version 6 -- because we don't want them checking in any more code. So we declare we're "feature complete" and all we're doing is finding the last few bugs, so actually near the end of the project, the spotlight sort of turns to the QA team in Release Engineering and Localization.
The engineers do get a little bit of a breather, so when the final few bugs come in, they can jump on them very quickly. But they do get a little time to think about the next release even before the previous one ships. We spend a lot of time with customers, with marketing, and reading the online discussions -- the Internet is a wonderful source of information. But then, as much as possible, we leave the previous release behind and move on to the next one."
PLANET PDF: Are you seeing or hearing anything so far that suggests the need for an Acrobat 6.x update or fix in the near future, or do things seem to be going pretty well?
WULFF: "I think we're extremely happy at how well things are going. We get a daily report from our customer support people. There are always going to be a few things, whether it's installing on versions of operating systems we weren't able to catch or things like that. But for a release of this size, we are extremely happy at how well it's being received by our customers. But we're committed to fixing any serious problems that might come up. We have a team that's dedicated just to that -- emergency patches, if we need that."
PLANET PDF: Acrobat 6 is now a family of products rather than a single one, which might suggest that it's more challenging from the Engineering and development perspective. But during much of its history, Acrobat has actually been a group of products -- not always the same products by the same names, depending on the version -- which has become a bit confusing for some over time. Do you sense that with the new Standard and Professional versions, we're now at a point where these names will be locked down for future versions?
WULFF: "I sure hope so. In the early days of Acrobat, we also had multiple versions, and I was very much against having multiple flavors in the early days. I thought it was more important to have one version out there that was successful. Acrobat's success really began to pick up with Acrobat 3 when we actually had it down to one version by then. But there's no question that with the success of Acrobat 4, 5 and the anticipated success of 6, that it was impossible to keep adding all these features and keep addressing all of these markets with one product. I think the time was definitely right with Acrobat 6 to say we'll have a Standard version and then we'll have a Professional version, which will have a lot more features and bring more value to the customer. I think -- I hope -- that we'll be sticking with Standard and Professional; and don't forget about Elements; and then there's the Adobe Reader. Even Reader comes in a couple different sizes -- the small Reader and the big Reader. And then all of the hand-held devices -- for the Palm, the Pocket PC and we'll be doing more in that space, too. I always try to keep things as simple as possible, but at some point you do have to split them up a little bit to really bring the right product to the right customers. Our goal is very simple: We want people to be able to view and print PDF on any device."
PLANET PDF: Since you mentioned alternative devices, I'm reminded that a number of years ago we discussed the prospect of PDF becoming a supported format on what was then a new technology, WebTV (now MSN TV, owned by Microsoft). It seemed at the time like the fixed display format of WebTV might lend itself to PDF, but it wasn't one of the filetypes initially supported. And it still isn't, last I heard -- but then WebTV never really caught on for various reasons. But Adobe obviously has increased its focus on devices beyond computers in the recent past. Will we see more of that?
WULFF: "There are a lot more devices out there then there were 10 years ago, and I think in the future you'll be able to view and print PDF on lots of devices that you can't today. That's definitely one of our missions. A lot of it has to do with the commercial success of the different devices. We're going to port to the most successful ones first."
WULFF: "Certainly going from trying to figure out what a customer would want in this new product category and trying to explain it to customers what it was in the first place in the early days to something that is now much more established. Everyone knows what it is, and it's now much more customer-driven. That's been a big change for us.
Another big change has been how people exchange files. If you go back to 1993, how did you exchange files with people? You tried email and email attachments -- didn't always work between computers. Maybe you had an FTP site, maybe you had a CD. It was just very difficult. The Internet certainly brought a very easy way to publish from one person to very large numbers of people. So that got us thinking a lot more about things such as PDF file size, and how do we make sure that reading a 1,000-page document on the Internet over a modem -- how do you make that work? And those were problems we didn't think about in the very early days.
The whole development process, as we've gone from a small development team to a large one, has certainly changed and become a lot more formal. We kept adding things like program managers and a larger Release Engineering team as we needed them. The really important thing, as Acrobat has become a larger part of the Adobe business, we've become lots more predictable with things like schedules and feature sets."
PLANET PDF: Again, as Jim King mentioned in our recent interview, there was a time when Acrobat wasn't widely popular even within Adobe, with some people even expressing an interest in discontinuing the product. That's certainly changed. For many people, Acrobat has now become the first product they think of when they hear the Adobe name.
WULFF: "I think Acrobat is a great example of where somebody had a vision -- born in about 1989 or 90 -- and a team of very hard-working people who were put together to provide the perspiration for that inspiration. It took longer for it to become a market success than maybe some other products. But the vision was always true. And the people that we added to the product continue to add visionary ideas even beyond John Warnock's original ideas, and have kept the mission alive. It's been a lot of hard work by a lot of very smart people. Sometimes these things take just a little bit longer. The network effect now is definitely alive with Acrobat. And as you say, it's now one of the most identifiable parts of Adobe."
PLANET PDF: Having seen the technology grow from its birth, what surprises and/or pleases you the most seeing what it has become and how it is being used today?
WULFF: "I think we're all very pleased with the success to see the vision turn into a reality. I don't want to say we're surprised by that because we had very high expectations from the very beginning. It's also just wonderful to work on a product when everyone knows what it is. No matter where I go, whenever I tell them that I work at Adobe, they instantly say 'Oh, yeah, I have Adobe -- I downloaded my tax forms' ... or whatever they did. And so that's a lot of fun. I spent a lot of my life working on products that nobody ever heard of or could even understand. It certainly has been fun to work with a lot of great and talented people over the many years. We have had some different people working on the different releases, but we also have a lot of people who have worked on it ever since Acrobat 1 or 2. It's been just a great mix of people.
And it's always a challenge to keep those people here, especially during those Internet years -- the dotcom temptations, etc. But the best part is that we invented a product category that didn't exist before Acrobat; it's become mission-critical for many people in their business. And it works! The product simply works. And that's probably the most gratifying of all.
And then we're also extremely happy about the third-party community that has developed around Acrobat. It's pretty amazing. We can't possibly implement all of the features -- we know that. But this product area is very large -- that continues to surprise me -- how large that space is and the number of features we could potentially implement. But we obviously can't do it all. We're very happy with our third-party development community to jump in there and to provide a lot of added value to the product."
PLANET PDF: We're hearing quite a lot of online chatter about the new 'Search' functionality in Acrobat 6. Can you talk a little about why Adobe revamped the 'Search' capabilities and methods, and briefly explain the advantages and key features are of the new version?
WULFF: "I'm glad you brought that up. I think the new 'Search' command is a good example of ideas we had percolating for a long time. A big part of Acrobat 6 was the completely re-designed or re-written user interface. So while we were doing that, it was just so obvious that it was now time to take all these great ideas we had about 'Search' and make them part of the new user interface. Even simple things such as searching for words and expressions across a directory or folder of PDF files -- such an obvious thing -- was really hard to do with Catalog. A motivated user could do it, but it was just way too much effort. So to just build that into the product was the right thing to do.
Another example is the ability to search PDF files across the Internet. It was a great opportunity. Google had already added the indexing feature, and we just added a very easy-to-use interface to it within the Search commands. I think that once people get done viewing and printing, the next-most-common thing they want to do with a PDF is Search. So we wanted to make sure that it was a first-class feature in Acrobat. With the UI redesign we thought it was the perfect time to do that. We spent a lot of time with the UI team and a lot of time researching that -- user tests, etc. -- and we're very happy how that turned out."
PLANET PDF: Can you give us any hints on where you see things going in the product's future?
WULFF: "Sure, I already alluded to supporting more platforms. That's one of the things you'll see from us. With our new team from Accelio -- and we've already made some announcements about our server direction and electronic forms, and building solutions around that -- making sure that the client and server work very cleanly together. That's certainly an area we're putting a lot of effort into.
Another area is more work in the area of PDF standards. I think a lot of people know about PDF/X for prepress exchange. We're also working with another standards group on something called PDF/A for archives. As we enter more industries, there are subsets of the PDF standard -- which is now a very robust standard with a very robust set of features -- that they want to use for their industry. Once you define that subset and everyone can agree that it's the subset they're going to use, then we'll of course provide tools to help generate those subsets or verify those subsets. We think this is a very important area, and it's an area in which we're working with many outside groups to accomplish.
One other thing I can mention: You've probably seen in Acrobat 6 a feature we call "Picture Tasks," and that's actually in the Reader -- the ability to generate a slideshow from a digital camera and from the Photoshop Album product, and then send it around and view it in your Adobe Reader using much more of a slideshow experience rather than just a normal document experience. That's another area we find very interesting.
And then we still have our long list of features, some of which come from customers and others that don't, that we will continue to work on for many years to come."
PLANET PDF: Thanks, Bob! This has been very enlightening -- we look forward to taking with you again, as always. It seems that after your initial experiences with a couple startups that never quite started up, you've had a major role in developing a product and technology that's showing no signs of slowing down at the end of its first decade. Congratulations -- and Happy Birthday (Acrobat and PDF), too -- from all of us here! [The image below is part of a keynote talk titled "Acrobat: The Early Years," presented by Adobe's Gary Cosimini at the recent PDF Conference.]
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.