A standard GNOME desktop on NixOS 26.05. Firefox is the browser: it sits in the dock and opens on the contest judge when you log in. Everything below is installed and ready the moment you log in — nothing to set up.

Want to run this environment yourself? See The GEHACK Live Image.

Desktop

   
Operating system NixOS 26.05
Desktop GNOME (Wayland)
Browser Firefox
Keyboard layouts US and NL (switch from the GNOME top bar)
Shell Bash by default; Zsh is installed too (with autosuggestions and syntax highlighting)
Trackpad Press Super+T (or the laptop’s touchpad key), or run Toggle Trackpad, to switch it off while typing and back on

Languages & compilers

Language Toolchain Notes
C GCC gnu17 standard; gdb and cmake included
C++ GCC (g++) gnu++20 standard; gdb and cmake included
Python CPython 3 & PyPy 3 Both interpreters installed; PyPy for speed
Java JDK 21 JAVA_HOME preset
Kotlin Kotlin compiler JVM-based; runs on JDK 21

Compile helpers

Pre-configured wrappers that build with contest-appropriate flags so you don’t have to remember them. Each takes the source basename.

Command Runs
mygcc sol gcc -std=gnu17 -Wall -O2 -static → sol.c to sol
mygpp sol g++ -std=gnu++20 -Wall -O2 -static → sol.cpp to sol
mypython sol.py PyPy 3 interpreter
myjavac Sol.java javac (JDK 21, UTF-8)
mykotlinc Sol.kt kotlinc (JDK 21) → JVM classes in the current dir 
$ mygpp solution      # compiles solution.cpp → ./solution
$ ./solution < in     # run it

Editors & IDEs

Pick whatever you’re fastest in — all are installed.

Editor plugins

These are the only plugins installed. You can’t install or update extensions during the contest.

VS Code extensions

Extension ID For
C/C++ ms-vscode.cpptools C, C++: IntelliSense and gdb debugging
CMake Tools ms-vscode.cmake-tools C, C++
Python ms-python.python Python
Pylance ms-python.vscode-pylance Python: language server
Python Debugger ms-python.debugpy Python
Language Support for Java redhat.java Java
Debugger for Java vscjava.vscode-java-debug Java
Test Runner for Java vscjava.vscode-java-test Java
Vim vscodevim.vim Off by default; turn on with Vim: Toggle Vim Mode

There is no Kotlin extension for VS Code; use IntelliJ IDEA or Neovim for Kotlin.

Neovim plugins

Plugin What it does
LSP (nvim-lspconfig) Language servers: clangd (C/C++), pyright (Python), jdtls (Java), kotlin-language-server (Kotlin)
nvim-treesitter Syntax highlighting and indentation for C, C++, Python, Java and Kotlin
neo-tree File tree
which-key Pops up the available key bindings as you type
nvim-web-devicons File-type icons

The leader key is Space. Preset key bindings:

Keys Action
Space e Toggle the file tree
g d Go to definition
g r List references
K Hover documentation
Space r n Rename symbol
Space c a Code action
[ d / ] d Previous / next diagnostic

JetBrains IDEs

PyCharm, IntelliJ IDEA and CLion come with their standard bundled plugins only. IntelliJ IDEA has JDK 21 preconfigured as the project SDK, so new Java and Kotlin projects build straight away.

Command-line tools

Debugging, profiling and the usual shell utilities:

gdb · valgrind · strace · cmake · git · tmux · screen · shellcheck · btop · htop · iotop · wget · curl · zip / unzip / 7z

Submitting solutions

The DOMjudge submit command-line tool is installed and pre-pointed at the contest judge — no URL to configure.

$ submit solution.cpp        # submit for the current problem
$ submit -p A solution.cpp   # submit explicitly for problem A

You can also submit from the DOMjudge web interface in Firefox: it is the browser’s homepage and the first bookmark on the toolbar.

Printing

The contest printer, PSGEWIS1, is set up as the default printer. Print from any application with Ctrl+P, or from the terminal:

$ lp solution.cpp

Extras

   
Offline DevDocs Full DevDocs mirror at https://docs.gehack.nl (also on the Firefox bookmarks toolbar) — no internet needed
Games GNOME games (Sudoku, Mines, Mahjongg…), SuperTux, SuperTuxKart, Neverball, plus terminal classics

Good to know