Hi,

MEPS is available at SqueakMap.
http://map1.squeakfoundation.org/sm/package/1e518e4f-119f-4a39-80eb-04bcbec6fc01

Description:

MEPS stands for Matching Extensions for PositionalStream. You can use this 
package to translate a BNF grammar into an equivalent recursive descent 
parser or scanner.

MEPS is simple enough for one-liners yet capable enough for complete parsers 
or scanners. See http://squeak.reider.net/MEPS/meps.html for details.

Cheers,
Alan