Original sentence: Frostwire is open source and claims to be free of any adware or spyware.However, while LimeWire is available in both free and paid versions, FrostWire is only being released in a free version (which its makers claim is equivalent to LimeWire's paid version)
Edited sentence: Because Frostwire is open source, it is, of course, completely free of any adware or spyware.However, while LimeWire is available in both free and paid versions (with the paid version, LimeWire Pro, ostensibly offering better searches and connectivity), FrostWire is only being released in a free version (which its makers claim is equivalent to LimeWire's paid version)