what clearcase plugin to use with eclipse

Question

Which Clearcase plugin should I use for eclipse 3.5+?

• which is easiest to use?
• which is most reliable?
• can any of the plugins handle workin

Answer 1

Worked well using HELIOS, but would not install under INDIGO.

Error "cannot be installed in this environment because its filter is not applicable".

Testing out the OpenSource alternative as suggested above. They work a little bit different from each other.