Cisco config checker

[Pete Kruckenberg]

Is there such a thing as a Cisco config checker, to allow off-line editing
of Cisco configs and check them before they're uploaded to the router?
Preferrably something that could be used in a Web/Unix environment as a
filter.

If not, does anyone know of a source for a complete definition of Cisco
configuration language, in some kind of standardized format, so I could
possibly generate a config-checker myself?

Thanks.
Pete.