Tunnel is a free Java 2.5D cave drawing program surveys based on Survex-compatible data which can also read and PocketTopo files.
It is used primarily to draw up CUCC Austria caves and the Three Counties System.
The defining feature (ie why you cannot use a standard drawing software for this application) is the ability to distort the maps to fit to changes to the underlying survey network.
The main alternative to Tunnel is Therion, which also solves this problem, but in a completely different manner and with a slightly steeper learning curve.
Download tunnel2019a.jar from the downloads page and double-click on it.
Read the inline help file online or from within the program.
Hoping to get this program into the nix repository. For now we can build it using this code:
nix-build --verbose --expr 'with import <nixpkgs> {}; callPackage ./tunnel_attempt.nix {}'
Or even better we can do: nix-shell --verbose tunnel_attempt2.nix nix-build --verbose tunnel_attempt2.nix