gdbm

If you are looking for a fairly simple, embeddable in memory database ( actually a hash), gdbm is just what you need. Based on the Unix dbm, it has a simple API and an LGPL license. Of course, there is nothing like SQL queries, Encrypted Relational DBs, transaction support and all that, but then, if you need that, there are bigger and more complex databases available out there. ( There was one recently out, from IBM, but it was all java).

Here is what GDBM's man page says

GNU dbm is a set of database routines that use extensible hashing. It works similar to the standard UNIX dbm routines.

Make

Adrian Reau has a good article on freshmeat, discussing the shortcomings of venerable make program.
Anyone who has ever tried to make a portable build system for more than a couple of platforms would agree that make is just not enough. There are so many heavily used, Gnu Make features that are not there on other unixes.

Unfortunately, the portability problem isn't solved by the use of Make replacements he has suggested. But for other problems , like recursive make, these (esp. cook) seem to be decent replacements. Unfortunately, the build chain never gets the importance it should (becuase our focus is to fix customer issues, and build problems are essentially developer issues).