http://www.creativecrash.com/downloads/applications/syntax-scripting/c/eclipse-maya-mel
I had a request recently for a mel syntax highlighter in Eclipse. I guess there’s still lots of legacy mel scripts that this would be nice to have. There was an mel/Eclipse plugin available but it hasn’t been recompiled in several years -I’m assuming it’s a dead plugin. Anyway, this one should fit the bill.