[plt-scheme] Standard project tools/libraries?

Hi folks,

Disclaimer: I haven't done any research into this myself other than to
look into SLIB. With that mentioned a question...

If I were to get started on a brand new Java project I would assemble
a sort of standard tool chest of libraries and tools.

For example I would figure out what persistence framework we would use
and what we would do for logging and unit-testing. Maybe we could
choose a few additional tools to like graphviz or Ruby to help with
some other aspects of the project.

If one were to start a new big project in Scheme, how would one
assemble his tool chest?

BTW: If you could recommend a "big" open/free source, system written
in Scheme one could review that would be great. For example, in
Haskell the first project one would probably examine is darcs.

Best wishes,

Grant