To develop Distance you need to have a working knowledge of the following:

• Distance for Windows. See, for example, Distance 6.2 Release 1 User’s Guide.
• Microsoft Visual Basic 6.0 programming
• Microsoft Data Access Objects (DAO)
• Microsoft Component Object Model (COM) i.e. ActiveX, etc.
• Fortran programming
  • Primarily Fortran 77 but some Fortran 90
• R scripting
  • For an introduction, see A (very) short introduction to R
• Geographic coordinate systems and projections.
  • See “Appendix B: Geographic Coordinates Systems & Map Projections” (PDF) from Strindberg, S. (2001) Optimized Automated Survey Design in Wildlife Population Assessment. Unpublished PhD Thesis. University of St. Andrews.
• ESRI Shapefiles:
  • See ESRI Shapefile Technical Description (PDF), a white paper produced by ESRI describing the internal format of a shapefile
  • You may also find Martin Wegmann’s Spatial data handling in R cheatsheet (PDF) useful.
• Using revision control
  • Git - for an introduction, see Version Control with Git
  • CVS - for an introduction, see Open Source Development with CVS
  • See also Version Control by Example