I have updated my Stata add-ons for sequence analysis (including Optimal Matching), and have now released it as a  package that you can install with the following commands:

 net from http://teaching.sociology.ul.ie/sadi

 net install sadi

Note that the software requires the moremata package (so “ssc install moremata” if you don’t already have that  — you may have to re-start Stata for that to take full effect).

The software uses plugins, which mean it is fast, but will only work on 32 and 64-bit Windows, and 32-bit Linux. It now avoids estimating distances for duplicate sequences, but does create the full N*N matrix. This makes a big difference where duplicates are common.

In this release, Hamming, OM and my variant-OM distances are provided, along with some utilities. Note that the variant OM distance is not guaranteed to be metric. In due course I will add a number of other distance measures.

There is a little more information available at
http://teaching.sociology.ul.ie/seqanal and an example Stata do-file at
http://teaching.sociology.ul.ie/seqanal/saditest.do

Please let me know if you have any difficulties installing or running this software.