There are several packages available for download as tarball files. Please be sure to download the correct package for your Linux version.
On the Server
Linux: This version works under any Linux flavor (i386, x86_64 and Raspberry Pi).
Asterisk: versions 11 or later with the manager interface enabled.
FreePBX: 2.11 or later.
On the Client
The Class software does not work with Elastix 3!
Centos - CLASS Free version: 3025
For Centos or other Redhat Based Distributions, including Elastix, PiaF, FreePBX distro, AsteriskNow, etc.
Debian - CLASS Free: 3025
For Debian Wheezy
Ubuntu - CLASS Free: 3025
For Ubuntu 14.04
Raspberry PI - CLASS Free: 3025
For Raspberry PI
Banana PI - CLASS Free: 3025
For Banana PI
BeagleBone - CLASS Free: 3025