You can draw some sequence diagram with simple text format by JavaScript. Example <!DOCTYPE html> <html> <head> <script type="text/javascript" src="../lib/seqdiag/parser.js" ></script> <script type="text/javascript" src="../lib/seqdiag.js" ></script> </head> <body> <figure id="diag"></figure> <script type="text/x-seqdiag" id="seqdiag-text"> seqdiag { A [label = "webapp"]; B [label = "DB"]; A -> B[