From README:

Aclgen is a tool to create minimal length ip access lists
and aggregated routing tables primarily for Cisco routers.

Aclgen is fast. It takes only 15 seconds to create a 17000 line
long access list for some 44000 entries of my routing table.

Aclgen is flexible. It accepts various input formats and
you can specify any output format by a printf like format-string.

Aclgen is intended to use in large scripts creating router
configuration from different databases.

Any contribution is welcome. Send me your script using aclgen.
I'll bundle it with the program.