Unfortunately SimpleIndex is for Windows only. This is true of most high speed document scanning applications, due to the fact that most document scanners only have Windows drivers.
However, SimpleIndex can output to databases and file shares on a Mac server. The fact that it does not have its own proprietary file system and database makes it a very good choice for Mac networks, since only the scanning workstation needs to be a PC.
Likewise, many users have reported great success running Parallels or Bootcamp on their Mac to allow the use of a Windows OS