The SharePoint Framework was announced on 4th of May and it introduced a new model to develop SharePoint webparts that is radically different from its predecessors.
Over the years SharePoint development required a specific environment, with SandBox and Farm webparts is required at least one server with SharePoint and Visual Studio to develop and debug, with the App model introduced in 2013 the SharePoint server is no longer needed but it requires Visual Studio and a Developer site collection hosted on Office 365.
With the new framework you are absolutely free to choose your environment, the only requirement is a computer able to run the latest web technologies, you can even use Mac OS or a Linux distro.
A few years ago I wrote an article explaining how to manually modify a SharePoint WSP solution using a specific software, over the years I got feedback about adware being added to the computers during the installation process of the software.
I recently tried to install this particular software and my antivirus automatically pop up saying that the file was not safe, to get rid of all this issues I decided to build a specific application to repackage all the files inside of the WSP solution.