Major Version Releases
Major versions of BigTree 4 are released approximately once per year. A major version is an update to the second number (i.e. 4.1 to 4.2). A major version update contains many new features as well as the potential for small API changes. Backwards compatibility breaking changes will be announced alongside the release but should be minor.
Minor Version Releases
Minor version releases are released approximately every two months but can sometimes occur more frequently when critical bugs are found. Minor version releases are generally maintained for the latest two Major Version branches (i.e. if 4.2 is the latest major release both 4.1 and 4.2 branches will be receiving minor version releases). Minor version releases mostly contain bug fixes but occasionally introduce small new features (especially when the major version release has been delayed).
Security related releases will continue to be introduced for older versions through a year after the bug fix end-of-life occurs.