The open source version of Sendmail recently suspended its planned implementation of the anti-spam weaponry collectively known as Sender-ID due to concerns about Microsoft's licensing terms. In response to this and other concerns being voiced in the free software/open source communities as Sender-ID is being considered as a new standard by the IETF, Microsoft has revised its Sender ID license to make it more acceptable to open source developers.
The new license has not yet shown up on the Microsoft Web site, but it is available online as a PDF attachment to an email submitted to an IETF mailing list yesterday.
Eric Allman -- author of Sendmail and CTO of Sendmail, Inc. -- followed up on the same mailing list yesterday to explain Sendmail's position on the new licensing terms. In that email, Eric wrote:
Sendmail, Inc. has worked with Microsoft to help them produce a patent license that will be acceptable for ourselves, the IETF, and the open source community at large. This message summarizes our position. The following discussion refers to the Royalty Free Sender ID Patent License (RFSIPL), dated 23 August. Harry has already posted it to the list, although it will take a few days to appear on the Microsoft Web site.
The executive summary is that we believe that the Sender ID technology is promising, and will hopefully be adopted. We believe that although not ideal, the RFSIPL and associated IP disclosures satisfy the IPR requirements of the IETF and are compatible with most major open source licenses. It would be extremely disappointing if this potentially useful technology to combat fraud and spam failed for reasons unrelated to its technological merits.
The revisions in the RFSIPL have clarified several important issues. Notably, it is now explicit that recipients of a Sender ID implementation who do not intend to redistribute the code do not need to get a patent license to use such an implementation. However, the license is not without restrictions.
Richard Stallman had previously taken exception to the original Microsoft license because it contained restrictions. He wrote last month in a letter to the same IETF mailing list that:
Microsoft's Sender-ID license is directly incompatible with free
software, regardless of which free software license is used. Free
software means users are free to run it, study and modify the source,
and to redistribute it with or without changes. Free to do so means
there is no requirement to ask or tell anyone that you are doing so.
The Microsoft license for Sender-ID directly forbids release of
software with all these freedoms, so it is impossible for any program
to be free software under Microsoft's regime.
I've been expecting to see something like this ever since Gates
started talking about spam. This license is an example of Microsoft's
strategy for killing off free software as an alternative to Windows.
Microsoft first patents something, then incorporates it into a format
or protocol, then tries to make it de rigueur while excluding those it
wishes to exclude. In the absence of resistance, Microsoft has a good
chance of imposing whatever standards it likes. Let us, therefore,
resist it here and now.
So while Allman and others may be hopeful that the new license is more agreeable to the free software/open source camps, it doesn't appear that debate over Microsoft's licensing for Sender-ID is likely to end any time soon.