Ranked in these QuestionsQuestion Ranking
Pro One of the fastest alternatives around
Unwrap 3D's developers claim that it's the fastest UV mapper on the market. Several benchmark tests and it's 64-bit unfolding core have proved that statement true.
Pro Support for many file formats
It supports more than 100 file formats. Some of these formats include FBX, DAE, ASE, DXF, LWO, OBJ, and DirectX.
Con Windows only
It's developed for Windows only. So no Linux or Mac version is available.