This is the Discovery-class exploratory cruiser USS Discovery NCC-79431. It was built in 2381 as a successor to the Ambassador-class. It was the first starship to incorporate a quantum slipstream drive, allowing velocities far greater than standard warp drive, and as such allowed realistic exploration missions to the Gamma and Delta quadrants.
The most unusual feature of this ship is the large exterior arboretum located at the rear of the saucer section. This was fitted as real trees were shown to reduce stress in crews on long term missions, similar to having families on the Galaxy class cruisers.
This ship is, quite obviously, non-canon, and was designed for an email RPG, which I am not a part of. I actually found this ship on www.asdb.net. I don't know too much about it, but if I played the RPG it's a part of, I probably would. I found the gentle curves of this ship somewhat difficult to reproduce, but I think I made a suitable compromise.