General Purpose Coarse-Grained Force Field 
Good news for multiscalers: Adaptive resolution simulation with MARTINI
New tool for fast backmapping
For details, read the paper, and/or try out the tool yourself
Review online: "Coarse grain modelling of protein–protein interactions"
Try out the next flavor of the Martini force field for lipids: Dry Martini. Still without olives.
In this version of Martini, water beads were completely removed from our simulation boxes. We adapted the interactions between beads by slightly tweaking the interaction levels and tuning some bonded parameter to reproduce the properties observed with the standard Martini force field. The new force field developed has been shown to nicely reproduce bilayer properties for a large variety of lipids.
Dry Martini is so far available only for lipids. A couple of small membrane proteins have been shown to perform equivalently compared to the regular Martini model; adaptation for proteins in (dry) solution is still in progress.
Curious? Excited? Download the parameter files and run your first Martini simulations without aqueous solvent!
Dry_Martini_v2.1
Wanna read more? Check this out:
C. Arnarez, J.J. Uusitalo, M.F. Masman, H.I. Ingólfsson, D.H. de Jong, M.N. Melo, X. Periole, A.H. de Vries, S.J. Marrink. Dry Martini: coarse grained implicit water force field for (bio)molecular simulations, JCTC, 11:260–275, 2015. (doi: 10.1021/ct500477k)
Review online: "The power of coarse-graining in biomolecular simulations"