I was attempting to compile subversion on my shared web hosting server and it finished with the following message:

You don’t seem to have Berkeley DB version 4.0.14 or newer installed and linked to APR-UTIL.  We have created Makefiles which will build without the Berkeley DB back-end; your repositories will use FSFS as the default back-end.  You can find the latest version of Berkeley DB here: http://www.oracle.com/technology/software/products/berkeley-db/index.html

At first glance this appears to be a bad thing… wtf is FSFS and why is subversion making a big deal about not using Berkeley DB as the backend? After some googling I came across a site outlining the benefits of FSFS over Berkeley DB and found it to be an interesting read, if you get time you should check it out.