Here is a collection of sites that maybe useful, sort of grouped
Record Sites
BDCC Google Map of Mendip Caves
CaveMaps - Surveys of the 'Yorkshire' caving area
DCUC registry - off line (July 2013)
Software
Auriga - Underground centreline and drawing software for palm
Compass - Centreline plotting
Cave Converter - Application that converts data between various software formats (Java, with open source code)
PocketTopo - Underground centreline plotting and sketching on Windows Mobile PDAs
RosettaStal - Cave survey data file format converter program (C++ source, Windows binary)
Survex - Centreline plotting and viewing program
Terrain Tool - Produces surface for Survex and Therion
Therion - Centreline, map and 3D model production and viewing
TopParser - Converts top files from PocketTopo to Therion, producing all the files needed
Tunnel - Map drawing program for use on Survex data
Walls - Tools for Cave Survey Data Management
WinKarst - Cave Mapping Software for Windows
Surveying
Cave Surveying and Mapping - An Introduction to Caves and Caving