C source code for PC questions

[P Wei]

Has anyone had the experience using the C source codes ( Concurrent C,
Lex, Yacc, Tools ) sold by Austin Code Works in Austin,TX---see ad in 
recent issue of PC Tech journal.
Are they worth the bucks ($45,$25,$25,$15, respectively) ? 
What are in the Concurrent C and Tools ?
Please mail any comments to me. I will summarize on the net if there
are enough stuff.
HP Wei