What is Forward Compatibility?
Forward compatibility is a characteristic where a system supports content produced for future versions of itself.
An older version of a system is forward compatible if it gracefully accepts inputs designed for the newer version of the system.
Compatibility in Software Development
Understanding version compatibility is essential for dealing with dependencies in software development.
If you update any libraries your project is using they might not be backward compatible with the older versions of dependencies you were on before. And it's possible that when you update those other dependencies they require a new version of their own dependencies. And so on.
This can be known as dependency hell. Where you chase your tail making no progress because you're stuck in a loop of updating dependencies, searching for specific versions that appease all the other dependencies.
This is especially complex because often different dependencies share other dependencies (but often request different versions of the same dependency). But that is why the concept of forward compatibility is important to understand.
Dependency hell is the result of compatibility issues between the different versions of software your application relies on.
Forward Compatibility Examples in Video Games
The concepts of backward and forward compatibitility are easily explained with video games.
If you have a PlayStation 4, it would be considered forward compatible if it could play games developed for the PlayStation 5. And unfortunately here, the PS4 is not forward compatible because game developers need to release a separate version of their game to be playable on the PS4.
The newer PS5 console however would be considered backward compatible since it is capable of playing games from the previous generation console.
Forward compatibility means this version of the system will gracefully accept inputs designed for the newer version of the system.
A library is forward compatible if it works with future versions of the programming language.
A gaming console is forward compatible if it works for games designed for future versions of the same console.
In general forward compatibility can be difficult to achieve because you design for a version that doesn't exist yet. Additionally, it's generally more profitable to make people buy the latest versions of things instead of letting them stay on older versions forever.
Regardless, now you have a full understanding of forward compatibility and how it affects you as a software developer!