MyFaces vs. Sun's Reference Implementation - latter not free?

Just a stupid beginner's question, which will be quickly solved, but I am curious.

http://www.irian.at/myfacesexamples/home.jsf says:

"MyFaces - The free JavaServer™ Faces Implementation"

Errr ... is Sun's implementation not fr开发者_C百科ee, then?

Thanks & Cheers Er

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I guess it could refer to MyFaces being free & open-source software, unlike (?) Sun's JSF implementation, even though the latter is "free as in beer". But note that official MyFaces website doesn't use such a designation.

Further reading: http://en.wikipedia.org/wiki/Gratis_versus_Libre

Edit: As pakore points out in comments, also Mojarra (codename for the JSF reference implementation) is "free as in liberty" (using the CDDL license). So, it remains somewhat unclear where the slogan "the free JavaServer Faces Implementation" at that MyFaces examples site actually stems from. Maybe it doesn't matter too much. :-)