A community implementation of .NET is splitting in two, hoping to protect Linux and open-source against potential patent claims from Microsoft.
The Mono Project plans to split between a core set of APIs that are based on ECMA specifications of Microsoft's C# and Common Language Infrastructure (CLI) and a stack that implements other Microsoft APIs for ASP.NET, ADO.NET, and Winforms.
Microsoft has promised it won't assert patent claims against non-Microsoft implementations of C# and CLI, but it has made no such clear promise on the rest.
de Icaza: no word on non-ECMA APIs
The distinction is important, as Mono has been used in a variety of open-source applications that can ship with and work on popular Linuxes such as Debian and Ubuntu.
Applications using the C# parts of Mono include the Banshee media player, the Gnome Due application installer, Beagle desktop-search, and the Tomboy note-taking application.
Mono leader Miguel de Icaza told The Reg: "The concern is Microsoft won't sue over the ECMA code but there's no word on the others so we are going to split those out so everybody isn't concerned."
ASP.NET is under Microsoft's Shared Source Initiative, which provides limited rights to view the Microsoft source code. ADO.NET is available under Microsoft's Public License. And Winforms come in a variety of open and copyrighted licenses.
The very presence of Mono in applications used by Debian and Ubuntu reached a crescendo last week, with GNU-daddy Richard Stallman calling it a threat to open-source because Microsoft could assert its claims over C# to kill Mono-based projects.
Stallman's comments followed what appeared to be a great deal of community politicking, debate, and personal attacks made through various email lists apparently designed to get people to boycott Debian and Canonical and force them to dump Mono, which is sponsored by Novell. Mono has been taking heat since Novell's controversial patent protection deal with Microsoft in November 2006.
In some cases, people have reacted to the anti-Mono wave.
One commenter on an Ubuntu mailing list promised his company would look into switching from Ubuntu to Fedora because Mono "is just too dangerous" and said he stood by the position taken by Stallman. He was speaking after The Ubuntu Technical Board said it saw no harm in Mono.
The sticking point was that since 2001, Microsoft has made Mono available on reasonable and non-discriminatory (RAND) terms rather than a royalty free license, a license Microsoft had promised it would adopt.
The sore point was what constituted "reasonable" as Microsoft could set the terms. de Icaza said nobody had followed up to make the ECMA C# and CLI specs available under the promised royalty free license.
Microsoft's promise Monday of availability under its Community Promise is designed to rectify that and satisfy critics of Mono. The C# and CLI parts of the Mono core can still be installed with the other part of the Mono stack, covering ASP.NET, ADO.NET, and Winforms. ®