Carbon Runtime Library Exception (RLE), which is in essence a GPL Exception, allows you to use the awesome Carbon library without releasing your software under GNU’s AGPL-3.0-only.

Some key aspects of the Carbon RLE are the following:

• One-Time Purchase (OTP): Once obtaining a copy of the RLE, it lasts forever without expiration date.
• Project-specific: Each RLE is tied to a single project of yours.
• Version compatibility: Each RLE applies to a specific branch or major version of Carbon (e.g. v1.y), enabling you to update the library to a more up-to-date version with the same RLE.
• Professional support: You also gain access to more advanced support regarding the library, as well as a private channel to make high-priority requests such as bug fixes or security vulnerabilities.