Fork

Software consists of program code, i.e. lines of text that tell a computer what to do. In many projects, this code is publicly visible and may be copied. A fork means: someone takes a copy of this code and continues developing it independently from that point on. The English word means a utensil with prongs, or a road splitting in two directions, and it describes exactly the image of a fork in the road. From the point of separation, there are two versions that move further apart with each change. Both retain the shared past but make different decisions about the future.

When a project splits into two camps

A fork is often the last option when those involved cannot agree. Anyone dissatisfied with the direction of a project doesn’t need to convince anyone. They can simply take the code and set their own rules. This gives the community power over the original operator.

This is exactly why forks are a risk for companies. When a company tightens the terms for a popular open project, developers often migrate to a fork. This became well known with the database MySQL: after it was sold to a large corporation, the fork MariaDB emerged, which is widely used today.

However, forks come at a price. Two teams now maintain similar code separately instead of working together on one. Users have to choose, and extensions sometimes only fit one version. As a result, many forks fizzle out again after a short time.

From copy to its own development line

Technically, a fork is surprisingly unspectacular. Developers manage code in a version control system that records every change with date and author. On platforms like GitHub, a single click is enough to create a complete copy including the change history. From then on, changes in the copy proceed separately from the original.

It’s important to distinguish between two meanings. The everyday fork on GitHub is usually harmless: you copy a project, improve a small detail, and propose the change to the original. A fork in the political sense only truly occurs when the copy permanently goes its own way and gains its own users.

With cryptocurrencies, the principle works similarly but has harsher consequences. All computers in the network must agree on the same rules. If part of the network changes the rules so that the old software no longer accepts the new data, this is called a hard fork. Two separate networks then continue to exist, as happened with Bitcoin and the fork Bitcoin Cash. If the new rules remain compatible with the old software, this is called a soft fork.

Forks in the AI world and in the headlines

In the AI industry, forks mainly appear with openly released language models. When a company makes the building blocks of a model freely accessible, others build their own variants on top of it. These are then fine-tuned for German, for medicine, or for programming tasks. Strictly speaking, this is not a code fork, but the media uses the word anyway.

Finished products you know are also forks. The Chrome browser and the VS Code programming editor have forks that remove advertising or add AI features. Many Linux systems are forks of other Linux systems.

In financial news, a fork is usually a signal of conflict or a shift in power. A common misconception is that a fork is theft. As long as the project’s license permits it, the fork is explicitly intended and entirely legal.