PENLAB
Nonlinear semidefinite programming solver
Availability
http://web.mat.bham.ac.uk/kocvara/penlab/
In YALMIP
PENLAB is invoked by using 'penlab' as solver flag in sdpsettings
Comments
Note that PENLAB is not actively maintained and has bugs which rather often cause the solver to fail in YALMIP. You will most likely not be able to solve your general problems using this solver.