Third party SSD optimization Yosemite
The TRIM command was introduced to facilitate “garbage collection” of deleted data, allowing the SSD to reset those “unused” blocks back to an “empty” state. This allows for better performance for many SSDs.

All Chameleon does is hack your SSD to enable TRIM. What the hack does is basically tell the OS that the non-Apple SSDs in the system are Apple drives so TRIM can be engaged with them.

Some people have not been able to boot up with Yosemite because it doesn't support TRIM but programs such as Chameleon have created a work around. The real issue is that the TRIM hack needed to be applied every time you upgraded to a new OS version, which was a real pain. But now that is not a issue. Hope this helps.