Interested in writing a domain-specific language for the CLR? Explore:
Microsoft DSL Toolkit CTP : This is a step towards Microsoft's Software Factories concept (which seems to be gaining buzz at the marketing level even though I'm not sure that the "factories" being released are actually aligned with the technical concept). Anyhow, very different from traditional parser construction tools.
ANTLR (my favorite, but perhaps just because I've become familiar with it) \<a href="http://www.knowing.net/ct.ashx?id=3b286e95-4d12-4061-a650-c4e5e7b4d8df&url=http%3a%2f%2fwww.plas.fit.qut.edu.au%2fgppg%2fDefault.aspx"" target=_blank rel="noopener noreferrer">Garden Points Parser Generator (YACC-style, used in the creation of RubyCLR. If I hadn't climbed the ANTLR learning curve, I'd probably turn to this.)
\<a href="http://www.knowing.net/ct.ashx?id=3b286e95-4d12-4061-a650-c4e5e7b4d8df&url=http%3a%2f%2fwww.devincook.com%2fGOLDParser%2findex.htm"" target=_blank rel="noopener noreferrer">GOLD Parser
\<a href="http://www.knowing.net/ct.ashx?id=3b286e95-4d12-4061-a650-c4e5e7b4d8df&url=http%3a%2f%2fjparsec.codehaus.org%2fNParsec%2bTutorial"" target=_blank rel="noopener noreferrer">NParsec
\<a href="http://www.knowing.net/ct.ashx?id=3b286e95-4d12-4061-a650-c4e5e7b4d8df&url=http%3a%2f%2fpdos.csail.mit.edu%2f%7ebaford%2fpackrat%2f"" target=_blank rel="noopener noreferrer">Packrat Parsing and Parsing Expression Grammars