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+* GINsim package for Nix
+  This repository packages [[http://ginsim.org/][GINsim]] for [[https://nixos.org/][Nix]].
+
+** Raison d'être
+   GINsim is extremely simple to install and run: just download the
+   JAR file from their [[http://ginsim.org/downloads][Download page]] and run it using =java -jar=.  I
+   wanted to get Nix to do it for me.  I also didn't want to add a
+   package to my local checkout of Nixpkgs.
+
+   The main goal of this repository is to simply show how to do all of
+   this.  It is first of all a Nix exercise, which allowed me to
+   better understand Nix (I've been using it for >4 years as of 2020,
+   but I still consider myself a beginner).  It may be useful for
+   people using GINsim as well.
+
+   The Nix files in this repository contain more comments than code in
+   the hope to be useful to other people and to older me.
+
+** Usage
+   To get GINsim, run the command =nix-build ginsim.nix=.  This will
+   create the symlink =result= in the current directory pointing to
+   the output directory of this derivation.  You can run
+ =result/bin/GINsim=.
+
+   Alternatively, you can run =nix-shell= (or =nix-shell shell.nix=)
+   to get a Nix shell in which you can run GINsim directly using the
+   command =GINsim=.
+
+** References
+   I relied extensively on [[https://nixos.org/nixos/nix-pills/index.html][Nix pills]] and on the [[https://nixos.org/nixpkgs/manual/][Nixpkgs manual]] when
+   writing this code.
+
+   A very helpful Nix and NixOS community can be found on the [[https://discourse.nixos.org/][NixOS
+   Discourse]].