The CXTM Test Suite provides a suite of test data for validating implementations of ISO 13250 Topic Maps using the new ISO 13250-4 standard for topic map canonicalization.
The first release, version 0.1, is now out: http://sourceforge.net/project/showfiles.php?group_id=104596
This includes 281 tests for XTM 2.0, LTM 1.3, TM/XML, and CTM (2008-05-15 draft).