GT.M V4.3-001D is now available (binary, source, and release notes). This includes a couple of fixes relevant to VistA, including in the areas of error trapping, and pattern matching (see the Change History section of the release notes). GT.M[tm] is a vetted, industrial strength, transaction processing application platform consisting of a database engine optimized for high TP throughput and a compiler for the M (aka MUMPS) programming language.
-- Bhaskar