Licensing Considerations When Integrating FOSS and Proprietary Software

Friday, October 29th, 2010

By CJ Fearnley

Recently, I was looking for resources to help explain the implications of integrating FOSS (Free and Open Source Software) with proprietary software. This question is important for any organization who might want to build an “embedded” or “dedicated” system or product which might include either their own proprietary software or third party applications. I discovered that most of the information available about FOSS licensing addresses this issue rather obliquely. This post will cover the basics so that such organizations can see how straightforward it would be to include FOSS in their projects. Standard disclaimers about my not being a lawyer apply.

Use of any software system requires understanding the software licensing involved. There are many dozens of FOSS licenses that could apply in your situation, so understanding the details is necessary to assess compatibility. In broad terms, these can be effectively summarized by the Debian Free Software Guidelines and The Open Source Definition. Any software that complies with those specifications will freely (in both the “freedom” and money senses of the word) permit running proprietary and FOSS applications on the same system. This is easier said than done. Since Debian has analyzed most common FOSS and quasi-FOSS licenses, their archive and their license page can be used to assess how the license might work in your situation (for example, anything in “main” would be OK for co-distribution and running in mixed environments). So we always start with Debian’s meticulous and well-documented analysis to assess any license.

From a high-level perspective, the requirements that FOSS licensing will impose on an organization wanting to include it with proprietary software will primarily be in the form of providing appropriate attribution (acknowledgement) and providing the source code for any FOSS software (including any modifications) shipped as part of an integrated system. Typically the attribution requirement can be satisfied by simply referencing the source code of the FOSS components. The source code requirement can be met by providing the source code for all of the FOSS distributed as part of the integrated system, for example, by placing it on a documented ftp site.

There are some subtle issues that may arise during the software development process if proprietary and FOSS code are “linked” together. In such cases it is necessary to ensure that code over which one wants to assert proprietary control is only combined with FOSS code that explicitly supports such commingling. So it is necessary for a company wanting to keep its code proprietary to keep it “separate” from the FOSS code used in the integrated system. The use of the words “linked” and “separate” is intentionally vague because the terms of each FOSS license will need to be examined by legal counsel to understand the precise requirements. In these situations, there are license compliance management systems that can be adopted to help ensure that this separation is maintained.

Those are the basic issues. The references below describe these and related issues involved with Linux & FOSS licensing in much more depth:

Seven Observations On Software Maintenance And FOSS

Monday, November 30th, 2009

By CJ Fearnley

The November 2009 issue of Communications of the ACM (CACM) has a very interesting article by Paul Stachour and David Collier-Brown entitled “You Don’t Know Jack About Software Maintenance”. The authors argue energetically for using versioned data structures and “continuous upgrading” to improve the state of the art of software maintenance.

The piece got me thinking about FOSS (Free and Open Source Software) and “continuous upgrading”. Here are seven observations on FOSS software maintenance that occurred to me as I reflected on the CACM article:

  1. FOSS projects “continuously” apply bug fixes and feature enhancements at no additional cost to their users. By applying these improvements “continuously”, the user reaps a steady stream of “interest payments” providing ever-improving security, performance, and functionality.
  2. Since FOSS incurs no licensing or license management costs, upgrading FOSS is not hindered by capital expenses.
  3. Typically support in FOSS projects is focused on the current stable version. Therefore, upgrading to the current stable version is the preferred way to receive the best support from FOSS communities.
  4. One of the key reasons behind Debian‘s strong track record of “continuous upgrading” is its way of handling the tricky issues involved with dependent library upgrades (such as libc6, libssl.so.0.9.8, & etc). The chapter on Shared Libraries in the Debian Policy Manual details a proven method to effectively handle library upgrade issues (including its sophisticated handling of versions).
  5. When upgrading is applied routinely and “continuously”, it becomes crucial to support customizations across upgrades which can be one of the biggest obstacles to a smooth upgrade (see my earlier post on customization and upgradeability). One reason for Debian’s effectiveness in this regard is its robust configuration file handling policy.
  6. It is worth noting that the “continuous” implied here is not the one emphasized in dictionaries (which takes its nuances from the mathematical / physics concept of “no interruptions” and the epsilon-delta definition that students of Calculus learn). That concept of “continuous” is impossible in systems administration which is necessarily discrete as are all computer operations. The connotation required here is, perhaps, “unending”, or “eternal” or somesuch.
  7. The “right” frequency for “continuous” upgrades is a complex tradeoff between business requirements and upgrade infrastructure maturity. Debian and Ubuntu provide vary mature support for “continuous upgrading”. They support the upgrade of production servers through release after release after major release with minimal downtime or risk of a glitch that could affect users. Their current release frequency of about 2 years may be the best we can do given the current state of the art of software maintenance. I hope we can learn to increase the frequency as better engineered upgrade policies are developed.

I prefer the name “eternally regenerative software administration” over “continuous upgrading”. It avoids the philosophical problems with the word “continuous” and emphasizes the active, “ecological” approach needed to envision the engineering of “regenerativity” in software. By that I mean software maintenance should involve building the system so each new version enables installation of the next while facilitating management of any customizations and integration with other software (including libraries and other “helper” applications). Regenerativity is the process of growth and change used by Nature itself. Software maintenance needs to follow similar principles.

Customization, Upgradeability and Eternally Regenerative Software Administration

Friday, October 16th, 2009

By CJ Fearnley

Mary Hayes Weier wrote an interesting article in this week’s edition of InformationWeek on "Alternative IT: CIOs are more receptive than ever to new software models". What is great about her article is how she captured the divergent views on IT models (such as SaaS, cloud computing, etc.) and gave nice vignettes of different organizations trying different parts of various models. I especially valued her use of cognitive dissonance to leave the reader thinking … better informed but without a firm conclusion.

There are so many parts of the article that I could blog about, but the one that touched the core of my thinking about “eternally regenerative software administration” was the quote by Bill Louv, CIO at GlaxoSmithKline, who said

"And here’s the rub: When you customize software, it’s difficult to implement future upgrades from the vendor"

Louv touched the very bane of eternally regenerative software administration! Software should accommodate both customization and upgradeability: these two elements of software administration are at the heart of my notion of eternally regenerative software administration: how to preserve customizations and provide smooth (near zero downtime with almost no glitches) upgrades through major release after major release. It is a big challenge, but in our experience the Free and Open Source Software (FOSS) communities are at the leading edge in finding solutions to these conflicting objectives. Here are some of the innovative ideas from the FOSS world which should serve as models or design patterns for all software developers (if only these ideas would become commonplace!).

First, Debian (a FOSS operating system which is the root of Ubuntu, Knoppix, Xandros and many other Linux distributions) requires that their official packages, a collection of software prepared for easy administration, must adhere to a very mature policy. Debian’s policy is a marvel in the FOSS world and to a very large degree is responsible for its strong support for both customization and upgradeability. I think Debian’s reputation for stability and maintainability is almost certainly due to their decision to develop a consensus-driven policy that its software must implement.

For example, the Debian package maintainer, Luigi Gangitano, for Drupal, a FOSS content management platform, did a great job making the software both customizable and maintainable. The package supports configuration of multiple virtual hosts which can all be upgraded at once! And the Debian drupal6 package stores the look-n-feel in /etc/drupal/6/themes/ so that each site’s GUI can be customized without interfering with upgrades. If only all web applications were built to be as maintainable as Debian’s Drupal package!

Another example is the overlay support included in RT: Request Tracker, a FOSS ticket tracking system. This allows putting replacement subroutines in special files in /usr/local/share/ which overlay or substitute the upstream code. This approach is more likely to break on upgrades, but it supports minimal changes to the business logic with a decent chance that upgrades will be smooth.

There are countless more examples from the FOSS world of innovative solutions to inter-accommodate customization and upgrades in support of eternally regenerative software administration. What are some of your favorite examples?