Revite
Revite is the official client maintained by the official Revolt team. It was the first client to be made and is the most fully featured option.
Development
Revite is written in TypeScript with the Preact framework. The client is currently being rewritten in SolidJS.
Source Code
The Revite client is completely open source. The code is available on Github. It is licensed under the GNU Affero General Public License v3.0.