You are looking at the EPICS State Notation Language compiler and runtime sequencer. For more information see the .txt files under documentation: Introduction.txt What all this is about, licensing, and other trivia Installation.txt How to download, build, etc Tutorial.txt Gentle introduction to SNL, some (sloppy) semantics Compiling.txt All about snc, the SNL compiler Using.txt How to create a working SNL program Reference.txt SNL syntax and built-in procedures Examples.txt Annotated example programs ReleaseNotes-2-0-and-older.txt ReleaseNotes-2-1.txt ReleaseNotes-2-2.txt Release notes KnownProblems.txt What the name says Plans.txt New features, ideas, and wishes You can also view the documentation online at http://www-csr.bessy.de/control/SoftDist/sequencer/