Spine is an open-source tool for developing and managing real-time applications and services. It is based on the Erlang programming language and provides an extensible framework for building distributed, fault-tolerant, and highly-available applications. Spine enables developers to rapidly develop, test and deploy scalable applications. It provides an easy-to-use interface and a powerful engine for building distributed and fault-tolerant applications. Spine provides a scalable and reliable messaging system, a distributed database, and a variety of other services and features. It also supports various languages, including Java and JavaScript. Spine makes it easy to create, deploy, and manage applications with minimal effort. It also provides support for monitoring and managing applications, as well as debugging and testing.
Much more affordable, however it lacks mesh functions.
Discontinued Official product page not available.
Discontinued KenneyNL Reported in the forums, Kenney Studio is discontinued. Source: https://itch.io/t/116590/purchase-kenny-studio
Synfig Studio
DragonBones
Spriter
Jpixel
Creature
Pixelesque
AnimeEffects
Kenney Studio
Marionette Studio
Rubber Hose 2
Sprite Something
You cannot make game animations in Synfig Studio, only animation clips and animation movies.