Is there supposed to be a zip there? Maybe the automated build is broken.
I have been unable to follow the steps successfully to produce my own zip.
1) Installed MinGW
2) Used wget to obtain 'Makefile' & 'PGP-KEYS'
3) Ran 'make'
... lots of success then ...
/home/travis/src/sasl/build-x86/gsasl-1.5.2/lib/gltests/../../../../src/gsasl-1.5.2/lib/gltests/zerosize-ptr.h:58: undefined reference to `rpl_getpagesize'
collect2: ld returned 1 exit status