Two separate processes govern changes to Scala:
The Scala Improvement Process (SIP) covers changes to the Scala language, the Scala compiler, and the core of the Scala standard library.
The Scala Platform Process (SPP) aims to establish a stable collection of libraries suitable for widespread use, with a low barrier to entry for newcomers.
Scala Improvement Process (SIP)
The SIP (Scala Improvement Process) is a process for submitting changes to the Scala language. This process aims to evolve Scala openly and collaboratively.
The SIP process covers the Scala language and compiler and the core of the Scala standard library. (The core is anything that is unlikely to be spun off into a separate module.)
A proposed change requires a design document, called a Scala Improvement Proposal (SIP). The SIP committee meets monthly to discuss, and eventually vote upon, proposals.
A SIP is subject to a review process. Proposals normally include proposed changes to the Scala language specification. Before reaching the committee, a proposal normally receives community discussion and review on the Scala Contributors forum. Please read Submitting a SIP and our SIP tutorial for more information.
Historical note: The SIP replaces the older SID (Scala Improvement Document) process. Completed SID documents remain available in the completed section of the SIP list.