Versionstring

Versionstring is a label used to identify a specific build or release of a software component. It typically encodes information about release history, compatibility, and build metadata, and is used by packaging systems, installers, and development tools to manage upgrades and dependencies.

Structure and components: Most versionstrings are composed of numeric identifiers separated by dots, such as MAJOR.MINOR.PATCH. Optional pre-release identifiers may follow the patch separated by a hyphen, and build metadata can be appended after a plus sign, for example 1.2.3-alpha.1+build.2010. The exact meaning of each component depends on the chosen versioning scheme.

Standards and schemes: The most widely used scheme is Semantic Versioning (SemVer) 2.0.0, where increments to MAJOR signal incompatible API changes, MINOR adds backward-compatible functionality, and PATCH provides backward-compatible fixes. Other schemes include CalVer, which encodes release dates, and epoch or date-based systems that use time-based identifiers.

Parsing and comparison: Versionstrings are compared according to defined rules. Pre-release versions have lower precedence than the corresponding release (e.g., 1.0.0-alpha < 1.0.0). Build metadata is not typically considered in precedence. Many languages and package managers provide parsing utilities and operators to support dependency resolution and version ordering.

Usage and implications: Clear versioning supports upgrade decisions, dependency constraints, and reproducible builds. It communicates compatibility and change intent between maintainers and users, affecting release planning, bug fixes, and deployment strategies.

Examples: 1.3.0, 2.0.0-beta.2, 3.1.4+build.123, 2024.11.3 (CalVer).