> ## Documentation Index
> Fetch the complete documentation index at: https://docs.qlty.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Runtimes

For plugins which are not distributed as native binaries, Qlty supports a variety of Runtimes which are generally virtual machines:

* Golang
* Java
* NodeJS
* PHP
* Python
* Ruby

Qlty is capable of installing packages using the package manager for each runtime (e.g. NPM for NodeJS).

## Runtime versions

By default, Qlty will run the latest version of each runtime that it has been tested against as-needed in order to run plugins.

It is also possible to specify the exact version of a Runtime to use with the following syntax:

```toml qlty.toml lines theme={"system"}
# ...

[runtimes.enabled]
python = "3.10.13"

# ...
```

With this configuration, Qlty will always use Python v3.10.13 when running PIP-based plugins.

## Optional runtime dependencies

The PHP and Ruby runtimes have additional, optional system dependencies. Please see the [System Requirements](/cli/system-requirements#optional-dependencies) for additional information.