I recently started a project which involves ingesting the Integrated Surface Data provided by the National Climatic Data Center. When looking at the various datasets that are available from the NCDC, the GSOD format seems to be pretty well traversed territory with plenty of folks having built tools in various languages to make it easier to make sense of it.
However, the same does not seem to be true of the Integrated Surface Data. The most challenging part is making sense of the "Additional Data Section" (I'd link to docs on that but they start on page 12 of the PDF I linked to above) mainly because it's a variable width and is separated broken up by any number of 3 letter delimiters (from amongst a pool of what looks to be hundreds of delimiters).
Any chance there is anyone out there who has worked or is working on this problem currently?