apollo/docs/guide/introduction/01-what-is-apollo.md

What is Apollo?

Apollo is a high-performance, modular RuneScape emulator with a collection of utilities for managing data files and plugins. Apollo targets revision 377 of the RuneScape client from late 2006. It aims to achieve parity with the game server of that time and preserve the history of the game in doing so.

Is Apollo free?

Apollo is open source and made available under the ISC license. The git repository for the project is hosted under the Apollo RSPS organization on GitHub.