Download the Pencil Code

The Pencil Code lives on GitHub — but unlike most repositories, it does not socialize using normal GitHub authentication. You can access it using SVN or Git. Yes, both. Because history is messy and developers have opinions.

Depending on your intentions, you can access the code in two distinct modes:

  • Read-only mode — observe the code like a respectful museum visitor.

  • Write access — join the crew and start rearranging the furniture.

For general time-travel concepts like branches, commits, and rebasing paradoxes, see Git: The Time Machine for Your Code. This document focuses specifically on obtaining the Pencil Code using your preferred weapon of choice.

Note

If you’re wondering “SVN or Git — which one should I use?” The answer is simple:

SVN — stable, linear, sensible. Like eating with a fork.

Git — interdimensional branching chaos. Like eating with chopsticks while skateboarding.

(Both approaches are valid lifestyles.)

Below is the Pencil-Code-specific access protocol for both read-only and write access.

Read Only (a.k.a. “Look but Don’t Touch” Mode)

If you just want to explore the code without leaving a trace, you can clone or checkout anonymously. No identity badge required.

SVN (for historians and minimalists):

svn checkout https://pencil-code.org/svn/trunk pencil-code

Git (for people who enjoy rewriting history even when they don’t have write access):

git clone https://pencil-code.org/git/ pencil-code

Congratulations! You now possess a spectator copy. Browse freely. Modify locally if you like — but pushing changes will be politely rejected.

Tip

Think of this as read-only Jedi training mode. You may swing the lightsaber, but it won’t cut anything yet.

Write Access (a.k.a. “Let Me In, I Want to Contribute!”)

So you want to actually contribute? Excellent — but that means the system must know who you are.

Although the repository lives on GitHub, the usual GitHub SSH key setup (see GitHub) will NOT work here.

Instead, follow the official Pencil Code procedure:

  1. Register at https://account.pencil-code.org

  2. Apply for write access to the main repository

  3. Ideally, choose the same USERNAME as your GitHub account — unless you enjoy future identity crises

Once approved, use the appropriate access method:

SVN (steady and predictable):

svn checkout --username=USERNAME https://pencil-code.org/svn/trunk pencil-code

Git (branch enthusiast edition):

git clone https://USERNAME@pencil-code.org/git/ pencil-code

Tip

To avoid re-entering your password every time, you can cache your Git credentials locally.

Set a timeout (in seconds):

git config --global credential.helper 'cache --timeout=####'

Or disable the timeout entirely:

git config --global credential.helper 'cache --no-timeout'

Warning

Using --no-timeout means your credentials remain cached for the duration of your session.

Do not use this on shared or multi-user machines, unless you enjoy the idea of your colleagues committing code as you while you’re getting coffee.

Warning

After write access is enabled, use your powers wisely. SVN users will quietly carry on as before. Git users will immediately create three branches and rewrite history twice before lunch.

You are now equipped to enter the Pencil multiverse — choose your timeline wisely.

What Next?

You now have the code. To actually work with it, hop over to Git: The Time Machine for Your Code for branching, staging, rebasing, and mild emotional breakdowns.

Happy hacking — and may your merges be ever conflict-free. Remember: with great power comes great responsibility… and occasional merge conflicts.