JointJS is a JavaScript library that developers use to build diagrams and visual editors into their own web applications, for example for workflows, network diagrams or process models. The core is open source under the Mozilla Public License 2.0. The maker also sells JointJS+, a commercial extension with additional features and support, under a separate licence. JointJS runs inside the developer's own application. It is therefore a European alternative to embedded diagramming and whiteboard components from commercial vendors such as Lucid or Miro.
JointJS is published by client IO s.r.o., a company based in Prague, Czech Republic, which also makes the Appmixer product. Because the library runs in your own application, you decide where data is stored; the vendor does not host diagram data. Only the website processes data, which the privacy policy says happens in the Czech Republic. No foreign parent company was found, and nothing has been published about ownership.