They are essential for developers working with version-specific legacy projects that require the 3.8.99 runtime for stability. 3. Community and Learning Resources

Use the full suite of rigging, meshing, and inverse kinematics (IK) tools.

You can download free example projects specifically configured for version 3.8.99 to study professional rigging techniques.

Because Spine 3.8.99 is a frequent "frozen" version for many long-term projects, the community provides free assets for it: