In general, the openFIRST project consistently releases packages in three different formats, Tar-Gzip, Tar-Bzip, and Zip.

The Tar-Gzip and Tar-Bzip versions contain unix-style end-of-line characters, which means that Microsoft ® Windows ® users who download these versions may see odd-looking black boxes throughout the code which make it difficult to interpret. The Zip file version contains Windows-style end-of-line characters, which eliminates the odd-looking black-boxes for Windows ® users.

The functionality of all software is equivalent in each of the three package types. Windows ® users should download the Zip version and may uncompress it using archive programs such as: Winzip or PK Zip. Users of other Operating Systems should download the file best-suited to their archive software of choice. In general, Bzip files provide the smallest download and the best compression, however some archive software may not support Bzip compression.

In summary:
Microsoft ® Windows ® users should download the Zip version.
Other Operating System users should download the Tar-Bzip version, or the Tar-Gzip version.