The Muir Russell "Climategate" inquiry team has put up the computer code they wrote to see how hard it is to obtain annual global temperature graphs from raw temperature data [cached: 1, 2]
The ICCER [Independent Climate Change Email Review] has provided example code to read and grid the GHCN [Global Historical Climatology Network] data set and produce an annual temperature series. The Review used such code in the "trial analysis" described in chapter six of our report.
(Actually, Chapter 6 of the Muir Russell report
is mainly a summary of the findings; the processing procedure is described in Appendix 7, pp. 150 et seq.)