SC Commerce is a privately maintained fork of Classic Commerce, which was itself a fork of WooCommerce 3.5.3 (initially developed for ClassicPress). However, unlike Classic Commerce, SC Commerce will work with the current version of WordPress and we plan to maintain this compatibility for all future WP versions. It will probably also still work with ClassicPress although this is no longer being tested.
The latest versions of WooCoommerce have notoriously become very bloated and slow, with the inclusion of an ever-increasing number of marketing and upsell promotions. These are basically designed to make money for Automattic (the parent company of WordPress and the owner of WooCommerce). In SC Commerce all connections to JetPack and WooCommerce Services have been removed. The result is a clean, light e-commerce solution that still retains all of the features that made WooCommerce such a powerful and popular plugin.
A full set of documentation is available on this site, and we have been compiling a library of snippets to add functionality without the need for extra plugins. It is also possible to use third-party plugins and extensions, as long as they are compatible with WooCommerce 3.5.3 and do not rely on JetPack or WooCommerce Services. Simply Computing do currently use a small number of these plugins on some websites but they are regularly monitored to ensure their continuing compatibility and functionality.