Mumsa is a tool for automatic assessment of alignment quality. A number
of alternate (to be compared) multiple alignments have to be generated
and submitted. 

Mumsa computes:
- the average overlap score (AOS), reflecting the difficulty of aligning
  the sequences
- multiple overlap score (MOS) indicating the quality of each individual
  alignment. 

Both scores range between one and zero.

CITING
Lassmann T, Sonnhammer EL. Kalign, Kalignvu and Mumsa: web servers for
multiple sequence alignment. Nucleic Acids Res. 2006 Jul 1;34(Web Server
issue): W596-9. doi: 10.1093/nar/gkl191.
PMID: 16845078; PMCID: PMC1538774