My Stuff

2010 Conferences

OSGi DevCon @ JAX London

February 23 - Keynote titled OSGi in the Enterprise: Agility, Modularity, and Architecture’s Paradox


March 22 - 25 - Tutorial on Modular Architecture

Über Conf

June 14 - 17 - Sessions titled Turtles and Architecture and Patterns of Modular Architecture


July 26 - 30 - Two sessions on rich mobile applications and one on agile development. Half day tutorial on software process improvement.

Tweets @ Twitter

re: #apple event "We sold more iPads than any PC manufacturer sold of their entire PC line." 2012-09-12

re: #Apple Event ""Our notebooks now rank #1 in the US in Market share in the last three months." 2012-09-12

Right on. I just won a Best Buy drawing worth $1000. Either that or I won a shiny new virus by clicking the link. Hmm...what to do. 2012-08-29

The #osgi alliance response ( to the @mreinhold #jigsaw announcement ( 2012-08-29

Good Q&A with @mreinhold on project #jigsaw. Modularity will change the way we design and run apps! 2012-08-28

LinkedIn Profile

The opinions expressed on this site are my own, and not necessarily those of my employer.

Farewell Blog, Hello POMA

Filed Under Development, General, OSGi | 6 Comments 

As the saying goes…all good things must end. As of today, my blog is shutting down!

I do intend to leave all content on-line so you’ll always be able to see a list of all 134 posts, but there won’t be any new posts for the foreseeable future. I’d like to thank everyone that has taken the time to read my often times long-winded posts. I hope you’ve found them useful.

For the past few years, I’ve written almost exclusively about modularity and OSGi (with a few other topics sprinkled in on occasion). To that end, I’ve decided to pursue a long overdue book project, tentatively titled Patterns of Modular Architecture (POMA). I hope you’ll decide to join me in my journey. Also, be sure to follow the book updates on Twitter.

So as to not disappoint those who have come to expect something a bit more verbose, I have managed to cobble together a few words explaining my decision in more detail. So if you want to know more, read on!

Story Behind the Story

Over the past few years of blogging, I’ve focused considerable energy on espousing the virtues of modularity and OSGi. From conceptual posts that discuss the important architectural benefits of modularity to simple examples that illustrate the benefit. From the beginning to the end, I’ve written about the benefits of modular architecture at a conceptual level, practical level, and have even provided some concrete examples. To the chagrin of some, I’ve even discussed the challenges that lie ahead. Of course, modularity and OSGi aren’t the only topics I write about. I’ve also written about agility, IT labor, metrics, and more. At some point though, the topics always came back to modularity and OSGi.

In the time that I’ve been focused on modularity and OSGi, the number of folks that access the content on this site have gone from less than 1000 visitors per month to more than 10,000, culminating in more than 100,000 pages served up and over a quarter million hits to the site each month. The blog was listed as one of the Top 200 Blogs for Developers, a Top Analyst Blog, and many of my posts are syndicated on JavaLobby. While still small by many standards, I recognized progress. And in general, the feedback I’ve received from the community is positive, though there is no doubt that at times, I’ve struck some nerves.

For those that read my posts, you already know that most tend to span many paragraphs. They require extensive writing time, considerable editing time, and careful review. It’s taken me hours to author many of them. And all of the content on this site has always been licensed under a Creative Commons Attribution-Noncommercial-Share Alike license. I vowed to never include any noise on the site, such as Google AdSense. It’s always been an earnest attempt to help developers improve the systems they create. A labor of love, you might say.

A while back, I introduced the modularity patterns, but didn’t elaborate much on the patterns themselves. Alas, that time has come. I’ve quickly realized that I do not have the bandwidth to continue with my long-winded posts and write a book. I’ve decided to pursue the latter and am hopeful that a book on modular architecture will have a far greater, longer lasting impact that serves as a capable ambassador for modular architecture. So while my blog may be silent, I have every intent to continue my advocacy of modular architecture, albeit in a way that I hope is more impactful.

I’ve decided to adopt an open and transparent approach to writing the book. The book’s website illustrates the book in it’s current form - a rough and incomplete draft to be sure. But I hope you’ll take the time to check it out, and offer any feedback you might have. I’ve created a Reviewers page that provides some guidance on the type of feedback I hope to receive. Also, be sure to follow the updates on Twitter.

By the way, this does not mean that I’ll necessarily cease my blogging activities altogether. In the past, I’ve published some articles to the APS Blog. Soon, the APS blog will also be shut down, and we’ll begin to blog on the Gartner Blog Network (GBN). So be sure to checkout GBN on occasion!

Thank you!

Ecosystems, Modularity, & OSGi

Filed Under Industry, OSGi, Platforms | 6 Comments 

Recently, I questioned whether OSGi and modularity would succeed in penetrating the enterprise. But what I really meant to question is whether OSGi will have the disruptive impact of which it’s capable. I asserted that if OSGi does succeed, it won’t be based on the technical merits of OSGi. It’ll be because of something else. Something trendy. Something fashionable.

Now, I could be wrong. OSGi adoption is certainly increasing, albeit slowly. And as case studies begin to emerge that tout the cost reduction, improved responsiveness, and time-to-market advantages of OSGi, adoption will likely continue to rise.

But adoption is one thing, disruption another, and I still have this nagging sensation that serves as cause for pause. What if something trendier, more fashionable surfaces, and OSGi is pushed into the backwaters? Will it really have the impact it’s capable of? You know…an “iPhone-esque” impact that raises the bar and redefines an industry. Not just evolutionary, but truly disruptive.

OSGi As Enabler

For OSGi to cross the chasm, it must enable something big that a business wants to buy. Maybe cost reduction, improved responsiveness and time-to-market benefits will be enough. But that’s easily perceived by many as a rather evolutionary impact. Not really disruptive.

Quite possibly OSGi will flourish in the data center, as organizations seek more adaptable platforms that lend them these benefits. But this doesn’t necessarily guarantee that development teams will leverage OSGi to build systems with a modular architecture. Because leveraging a platform built atop OSGi is separate from building modular software systems, even though OSGi enables both.

Without something trendy that promises real benefits, it’ll get brushed under the carpet like what has happened to many technologically superior solutions. Perhaps it’s already happening, with all of the hype surrounding the cloud. Or maybe it’ll be the cloud that helps OSGi cross the chasm. OSGi doesn’t obviously enable the cloud, but OSGi can enable the dynamic and adaptive runtime benefits of the cloud.

But again, this doesn’t mean that teams will begin leveraging OSGi to design modular software. It only means that the platform itself is adaptable. Of course, there is benefit in that. But if that’s the route that is taken, teams will still continue to develop monolithic applications that lack architecturally resiliency, and the full benefit of OSGi (and modularity) will not be realized.

The Disruption

OSGi has the potential to have have a much broader impact, affecting everyone from the developer to those working in the data center.  So what might this trend be that will propel OSGi to stardom?

OSGi enables ecosystems!

Now, you’re thinking I’ve gone on the deep end, perhaps? But give me a chance…let me explain.

A Bit of [Recent] Platform History

To start, I want to take a brief walk down memory lane. Not too far back though, but far enough so that we can see how important the ecosystem is in today’s most successful platforms. And these platforms span a range of markets, from mobile to social media. But each are successful in large part due to a thriving ecosystem.


In 2007, Apple released their first generation iPhone. Without question, the device revolutionized the mobile phone industry. While the device offers a great user experience that has certainly played a role in its surging popularity, people flock to the iPhone today because of the wealth of applications available. Yeah, “there’s an app for that.”

Apple, recognizing the power of this ecosystem, now delivers the iPad. With fewer preinstalled applications than the iPhone, Apple is counting on the ecosystem to drive adoption. The more consumers who flock to the device, the more developers who flock to the platform to deliver applications. As more applications become available, consumers will buy more iPads. The ecosystem fuels itself. Apple has simply provided the environment for the ecosystem to thrive.


In 2003, the Eclipse team was thinking of ways to make Eclipse more dynamic. Their decision to use OSGi to create a rich client platform that supports plug-in architecture was the first step toward the resulting ecosystem we know today. One of the reasons developers use Eclipse is because there are an abundance of plug-ins available that allow them to do their jobs more effectively. Other developers create Eclipse plug-ins because Eclipse is a popular IDE used by many developers. Again, the ecosystem fuels itself. The Eclipse team provided the environment that allows today’s Eclipse ecosystem to thrive.

If you’re interested, you can read more about the history of Eclipse and OSGi.


Arguably, Hudson is today’s most popular continuous integration server. But it hasn’t always been. Before Hudson was CruiseControl. And while CruiseControl did help development teams get started on their path toward continuous integration, it was also unwieldy to use in many ways. With Hudson’s plug-in architecture, developers have the ability to extend the tool in ways the original creator couldn’t imagine or couldn’t find the time to do himself. Kohsuke created Hudson and gave the development community a new platform for continuous integration. With its plug-in architecture though, he also provided an environment that allows the Hudson ecosystem to thrive.

Social Media

Facebook. MySpace. Twitter. Each are examples of social media tools with a strong developer community that creates extensions to the platform that users can leverage to enhance the experience. Facebook Developers. MySpace Developer Platform. Twitter API. Each allows the ecosystem to thrive.

And Others

These are just a few examples. It’s easy to find other platforms with similar ecosystems, as well. The ease with which Wordpress themes and plug-ins can be developed and used to enhance a Wordpress website is another example. In fact, many content management systems provide similar capabilities. A large reason why the Firefox web browser has emerged as the preferred web browser is the ease with which add-ons can be installed that extend the capabilities of the browser. The Atlassian Plugin Framework is another example that uses OSGi, and platforms such as and SharePoint have built (or are trying to build) similar ecosystems.

The Power of Ecosystems

Aside from Eclipse (and Atlassian), none of these other platforms leverage OSGi. Yet each are wildly successful because of two reasons:

  • An environment was created that allowed an ecosystem to form and flourish. This environment includes a platform and a marketplace.
  • A group of customers and developers converged on the marketplace and fueled growth of the platform. The result is a self-sustaining ecosystem.

If you look at many of the more popular platforms that have emerged over the past decade, they tend to possess a similar characteristic - a community of individuals dedicated to providing great solutions leveraging the foundation of the platform. OSGi and modularity enables ecosystems on the Java platform.

Ecosystems and the Two Faces

I’ve already talked about the two faces of OSGi - the runtime model and the development model. I’ve also explained how one could possibly see widespread adoption while the other has little impact. A strong ecosystem surrounding OSGi and modularity must leverage both. Developers would create reusable modules, implying they are designing modular software. For development teams to leverage these modules, they must be using a platform that supports the runtime model.

CBD Has Already Had Its Day, You Say?

Now some of you might be arguing that this sounds a lot like the component based development (CBD) fad of the 1990’s. True…to an extent. Certainly these ideas are not new. But there are also some striking differences between that which OSGi enables and the CBD fad that has come and largely gone, or whose promise was never fully realized.

Foremost, the CBD fad was focused almost exclusively on visual components, such as ActiveX. While some attempted to create components for the Java platform, the movement largely failed to go mainstream. Instead, Java EE grew in popularity and for a number of years, garnered everyone’s attention. Why did this  happen?

IMHO, the answer is fairly simple. Even though numerous marketplaces emerged that allowed the consumer and producer to come together to buy and sell components, there was never a suitable component execution environment. That is, an environment that would support dynamic deployment, support for multiple versions, dependency management, and, in general, complete control over all components currently executing within the environment. ActiveX components did have an execution environment (though did not support each of these capabilities), but Java did not. Today, in OSGi, Java has the requisite execution environment!

The Ecosystem

It’s easy find holes in this idea. To explain why it cannot work. Yet, it’s happening elsewhere, so why not on the server…in the enterprise? Certainly there are a variety of different ways such an ecosystem could manifest itself. Possibly multiple ecosystems emerge like what we see in the mobile market today.

But for a moment, imagine the world where you have the ability to easily assemble a platform from pre-built infrastructure modules that exactly meet the demands of your application. You might purchase these modules, you might choose to use open source modules, or you might build them yourself. For those you don’t build, you obtain from a module marketplace, possibly deploying them to your [cloud] environment.

And when you choose to use a module, it’s dynamically deployed to your environment. The modules it depends upon? You’re given the option to purchase and deploy them, as well. You develop your software modules using the sound principles and patterns of modular design to ensure loose coupling and high cohesion. As you roll out your business solution modules, you simultaneously deploy the additional infrastructure modules that are needed.

In this marketplace, modules are sourced by multiple vendors. Some large. Some small. Neither the stack, nor your applications, are monolithic beasts. Instead, they are a composition of collaborating software modules. Your infrastructure isn’t necessarily tied to a specific vendor solution. The option always exists for organizations to purchase modules from different providers, easily swapping one provider module out with another.

The ecosystem flourishes. Developers flock to sell their latest creation. Organizations seek to add amazing capabilities to their rightsized environment at a fraction of the cost compared to what they are accustomed to today. The business benefits are real. The technical advantages are real. And the resulting ecosystem is sustainable.

A successful ecosystem demands both the runtime model and development model. And today, OSGi is the only standard technology that will allow this type of successful ecosystem to form on the Java platform. But will it happen? We may have a ways to go, but it sure would be cool! And it would be a shame if we lost this opportunity.


Note: If you’re interested in ecosystems more generally, you might want to see the great TED talk by Dan Barber, “How I fell in love with a fish.” It’s very entertaining, informative, and worth 20 minutes of your time. His discussion on sustainability is truly fascinating!

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