Ted Leung talks about the open sourcing of Functional Objects Dylan and what it means to him. Another interesting language in the same vein as Arc is Goo.
From Ted's post I see he worked for Taligent. I used Taligent's CommonPoint while working for a company called Sapphire Technology in the mid 90's. It was a nice system and they had a lot of great ideas. It's a shame it never took off. It's also a shame it used C++ but given the time it was developed C++ was all the rage.