Microsoft has announced today the general availability of SharePoint Framework (SPFx 1.0). Quite the milestone!
Over on Office Dev Center there is a document called SharePoint Framework (SPFx) enterprise guidance, which offers a thorough rundown for developers. GitHub also has the release notes, which is recommended reading if you are going to install immediately. If you’d prefer your details lighter you can read the official SharePoint Framework release announcement from Microsoft on Office Blogs: SharePoint Framework reaches general availability—build and deploy engaging web parts today.
Sources: Microsoft – Office Dev Center; Office Blogs & GitHub