  We present the latest version of micromegas, a code that calculates the relic
density of the lightest supersymmetric particle in the MSSM. All tree-level
processes for the annihilation of the LSP are included as well as all possible
coannihilation processes with neutralinos, charginos, sleptons, squarks and
gluinos. The cross-sections extracted from CalcHEP are calculated exactly using
loop-corrected masses and mixings as specified in the SUSY Les Houches Accord.
Relativistic formulae for the thermal average are used and care is taken to
handle poles and thresholds by adopting specific integration routines. The
input parameters can be either the soft SUSY parameters in a general MSSM or
the parameters of a SUGRA model specified at some high scale (GUT). In the
latter case, a link with Suspect, Softsusy, Spheno and Isajet allows to
calculate the supersymmetric spectrum, Higgs masses, as well as mixing
matrices. Higher-order corrections to Higgs couplings to quark pairs including
QCD as well as some SUSY corrections (deltaMb) are implemented. Routines
calculating (g-2), bsgamma and bsmumu are also included. In particular the
bsgamma routine includes an improved NLO for the SM and the charged Higgs while
the SUSY large tan(beta) effects beyond leading-order are included. This new
version also provides cross-sections for any 2->2 process as well as partial
decay widths for two-body final states in the MSSM allowing for easy simulation
at colliders.
