Cross platform development is always an interesting challenge. Often it can be useful to identify or expose bugs that might be less visible on some platforms, or even on some compilers.
With cross platform development comes some important questions of software freedom. There would be no true software freedom if we said we would permit our software to compile and run only on specific platforms, that is after all what proprietary software vendors often do. However in GNU Telephony we do principally develop and test our software on GNU systems specifically and do not have expertise in or interest in supporting proprietary ones.
If people wish to work on or support other platforms also, they are certainly free to do so. As one of our goals in GNU Telephony is ubiquity, this is essential. However, unlike some groups who choose such goals, or distributions who choose “popularity” as their essential goal, we will never do so if it means also compromising the freedom of our contributors and users. Given this, if people want to submit patches for building and running on other platforms, we are happy to take such patches in, so long as they do not break features or functionality on free software platforms, and do not impose any additional restrictions on how we convey software to others.
For those who do choose to develop on or for Microsoft Windows, and wish to contribute to our packages, we do suggest using the mingw toolchain hosted on Debian GNU/Linux. We have done some preliminary tests with this, and have built things which then do run in wine. This does make it possible to do a complete build and qa test cycle for applications that will run on Microsoft Windows systems using entirely free software tools and platforms, as well as making it easier to avoid traps in undocumented proprietary api’s. We will accept patches and bug fixes from those who do build on proprietary compilers as well, assuming there is no restrictions or breakage to do so, since, as I note different compilers sometimes do expose useful bugs, however our desire is to support development tools and platforms that do support and encourage software freedom.
Software freedom and complete free software platforms is our projects essential goal, for without it, there is no possibility for communication privacy or security. This makes fully free software platforms, which are hostile to hosting malicious features or hidden backdoors, equally essential. While we do the best we can to facilitate secure communications in our packages, we do not recommend using or running our software on proprietary platforms, as we consider these untrustworthy and potentially insecure by design.