QMapshaper is a QGIS plugin written in Python that allows user to run NodeJS tool mapshaper. It can be installed from plugin manager in QGIS. Documentation is available on the website.
Plugin makes available two important tools from mapshaper. Topological generalization and saving data to TopoJSON format. To work the plugin needs NodeJS and mapshaper to be installed locally.
The main benefit of the tool is that there is no need to export data from QGIS to used them with mapshaper and then to import them back. These steps are handled through the plugin. The functionality is available as both processing tool, that can be used as part of complex workflows, and as an interactive UI tool.