On 26 Apr 2010, at 11:04, Stefan Sobernig wrote:

Well, there is a slight difference between the [package] and TEA versioning schemes. While for [package] version numbers, compatibility is only indicated by the major version number (*1*.2.0 vs. *1*.6.0), this is not a strict requirement for TEA version numbers. Here, as for the Tcl versioning (8.*4* vs. 8.*5* vs. 8.*6* vs 9), the minor number can indicate possible incompatibilities. I do not say that this distinction between [package] and TEA versioning makes any particular sense (apart from the Tcl stubs mechanism, probably). XOTcl has always followed the TEA approach from what i can tell and, while being very keen to avoid backward incompatibilities, does not give firm guarantees here.

Hm, I don't believe that is correct? In Tcl the minor number should not indicate incompatibilities to the script at all. Basically all 8.0 scripts should run fine on 8.5. At least I can't think of any cases where this has not been true, and that's the main reason why some TIPs have been considered for 9.0 and not earlier.