SCMtools

SCMtools is a software library that provides an abstraction layer for interacting with different source control management (SCM) systems. It defines a uniform API that allows applications to perform common repository operations without being tied to any single SCM. The library is designed to support multiple backends, each corresponding to an SCM such as Git, Subversion, Mercurial, Bazaar, and Perforce, among others.

At the core of SCMtools is an abstract tool interface, with concrete backends implementing the required methods. Typical capabilities exposed by the backends include retrieving file contents, accessing historical revisions, generating diffs, obtaining file histories, and providing blame or annotate information. Implementations may interact with SCMs through system commands, libraries, or other external interfaces, and they handle aspects such as authentication, encoding, and path translation as needed.

SCMtools is intended to be extensible. Developers can add new backends by implementing the repository tool interface and integrating them into the toolkit, enabling applications to work with additional SCMs in a consistent way. The library often includes support code for normalization of data across different SCMs and for common error handling and caching strategies to improve performance and reliability.

In practice, SCMtools is used by code hosting, code review, and automation tools that must support multiple SCMs with a single, cohesive interface. It originated within the ecosystem of Review Board, a web-based code review tool, where it provides the backbone for interacting with various repositories in a uniform manner.