macsig 0.8 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. Macsig for Mac lies within Internet & Network Tools, more precisely General. We recommend checking the downloaded files with any free antivirus.
From the developer:
Mac OS X data client for ampsig: the progressive sig
ampsig is a PHP script that generates an image to display select information about your computer.