CDO is a collection of command line Operators to manipulate and analyse Climate
model Data. Supported file formats are GRIB, netCDF, SERVICE, EXTRA and IEG.
There are more than 250 operators available. The following table gives a short
overview about the main categories.

* File information (info, sinfo, diff, ...)
* File operations (copy, cat, merge, split*, ...)
* Selection (selcode, selvar, sellevel, seltimestep, ...)
* Missing values (setctomiss, setmisstoc, setrtomiss)
* Arithmetic (add, sub, mul, div, ...)
* Mathematical functions (sqrt, exp, log, sin, cos, ...)
* Comparision (eq, ne, le, lt, ge, gt, ...)
* Conditions (ifthen, ifnotthen, ifthenc, ifnotthenc)
* Field statistic (fldsum, fldavg, fldstd, fldmin, fldmax, ...)
* Vertical statistic (vertsum, vertavg, vertstd, vertmin, ...)
* Time range statistic (timavg, yearavg, monavg, dayavg, ...)
* Ensemble statistic (enssum, ensavg, ensstd, ensmin, ...)
* Regression (detrend)
* Field interpolation (remapbil, remapcon, remapdis, ...)
* Vertical interpolation (ml2pl, ml2hl)
* Time interpolation (inttime, intyear)

WWW: http://www.mpimet.mpg.de/fileadmin/software/cdo/