This analysis was done by Petter Reinholdtsen in http://people.skolelinux.org/pere/blog/Is_Ogg_Theora_a_free_and_open_standard_.html
For a while now I have tried to figure out of Ogg Theora is a free and open standard according to this definition. Here is a short writeup of what I have been able to gather so far. I brought up the topic on the Xiph advocacy mailing list in July 2009, for those that want to see some background information. According to Ivo Emanuel Gonçalves and Monty Montgomery on that list the Ogg Theora specification fulfils the Digistan definition.
Free from vendor capture?
As far as I can see, there is no single vendor that can control the Ogg Theora specification. It can be argued that the Xiph foundation is such vendor, but given that it is a non-profit foundation with the expressed goal making free and open protocols and standards available, it is not obvious that this is a real risk. One issue with the Xiph foundation is that its inner working (as in board member list, or who control the foundation) are not easily available on the web. I've been unable to find out who is in the foundation board, and have not seen any accounting information documenting how money is handled nor where is is spent in the foundation. It is thus not obvious for an external observer who control The Xiph foundation, and for all I know it is possible for a single vendor to take control over the specification. But it seem unlikely.
Maintained by open not-for-profit organisation?
Assuming that the Xiph foundation is the organisation its web pages claim it to be, this point is fulfilled. If Xiph foundation is controlled by a single vendor, it isn't, but I have not found any documentation indicating this.
According to a report prepared by Audun Vaaler og Børre Ludvigsen for the Norwegian government, the Xiph foundation is a non-commercial organisation and the development process is open, transparent and non-Discrimatory. Until proven otherwise, I believe it make most sense to believe the report is correct.
Specification freely available?
Anyone may freely use and distribute the Ogg and [Vorbis/Theora] specifications, whether in private, public, or corporate capacity. However, the Xiph.Org Foundation and the Ogg project reserve the right to set the Ogg [Vorbis/Theora] specification and certify specification compliance.
The Ogg container format is specified in IETF RFC 3533, and this is the term:
This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.
All these terms seem to allow unlimited distribution and use, an this term seem to be fulfilled. There might be a problem with the missing permission to distribute modified versions of the text, and thus reuse it in other specifications. Not quite sure if that is a requirement for the Digistan definition.
There are no known patent claims requiring royalties for the Ogg Theora format. MPEG-LA and Steve Jobs in Apple claim to know about some patent claims (submarine patents) against the Theora format, but no-one else seem to believe them. Both Opera Software and the Mozilla Foundation have looked into this and decided to implement Ogg Theora support in their browsers without paying any royalties. For now the claims from MPEG-LA and Steve Jobs seem more like FUD to scare people to use the H.264 codec than any real problem with Ogg Theora.
No constraints on re-use?
I am not aware of any constraints on re-use.
3 of 5 requirements seem obviously fulfilled, and the remaining 2 depend on the governing structure of the Xiph foundation. Given the background report used by the Norwegian government, I believe it is safe to assume the last two requirements are fulfilled too, but it would be nice if the Xiph foundation web site made it easier to verify this.