It&#x27;s mutual. Unix didn&#x27;t solve problems for developers of large systems that stand on the shoulders of open source software libraries by failing to provide dependency resolution or versioning + namespacing source&#x2F;built files. (An obvious [non-]decision given the timeline of its inception and intended usage, but a failure nonetheless.)<p>So then we got some of the former with system package managers designed for system administrators and some of the latter with version control&#x2F;build systems&#x2F;dependency tools designed by and for software developers, but they don&#x27;t meet in the middle.<p>Docker is mostly used to just bridge the gap and force the system package manager to be a per-app-namespaced dependency&#x2F;build support tool.