Open-source backend software

4203 open-source libraries, tools and applications tagged backend, ranked by how closely backend is their primary purpose, then by adoption and maintenance health. Each entry links to a page with sources, use cases and when to choose or avoid it.

4203 products, primary matches first, then adoption-weighted; health v2 shown.

Product	Health v2	Stars	Maturity
outerbase/starbasedb StarbaseDB is an open-source, scale-to-zero SQLite database exposed over HTTP and WebSockets, built on Cloudflare Durable Objects. It provi…	61	1164	abandoned
JakeWharton/retrofit2-kotlinx-serialization-converter A Retrofit 2 Converter.Factory that lets Retrofit use kotlinx.serialization for serializing request bodies and deserializing response bodie…	10	1054	abandoned
polarphp/polarphp polarphp is an alternative compiler and runtime for the PHP programming language, rewrapping the Zend VM and adding a new runtime library (…	32	1037	abandoned