Why Google and Other ECM Companies Cannot Provide VCS Services

Google and other Enterprise Content Management (ECM) companies face significant challenges in providing robust Version Control System (VCS) services due to the inherent limitations of their storage subsystems. These subsystems evolved from the concept of shared files, leading to several key limitations:

Single File Versioning: The storage subsystems of these ECM companies are designed to manage only single file versioning. This means they can handle versions of individual files but cannot correlate versions across multiple files within a project.
Internal Version Information: In systems like Google Docs, version information exists inside the files and is not externally visible until the file is opened. As a result, they can only provide the latest snapshot of a document without a comprehensive history of project developments.

Lack of VCS Features

Due to these storage limitations, ECM companies cannot offer several critical VCS features:

Lack of Correlated Versioning: Without the ability to correlate versions of multiple files, it is impossible to track the evolution of a project as a whole. This limits the ability to understand how changes in one document relate to changes in others.
Absence of External Version Control: Since version information is embedded within files and not managed externally, there is no way to view or manage document history without opening each file individually.
Missing VCS Features: Essential VCS features like tagging a stable or verified set of documents are not available. These features are crucial for ensuring consistency and reliability in document management and project tracking.
Inability to Create Branches: Unable to create branches suitable for the independent development of subsets of documents with subsequent merging into the main line with automated verification.