Pencil is an open source user interface drafting tool that Evolus builds on Mozilla 's technologies . This tool helps analysts and application interface developers to quickly draw application interfaces to document communication with customers in the process of collecting requirements or as a basis for the team. application development. The Pencil tool building project is one of Evolus' efforts to give back to the community. It is for that reason that Pencil has been released as an open source tool (GPL license) so that anyone can have the opportunity to use and access its source code to adjust and upgrade. . Pencil can be deployed as an add-on to the Mozilla Firefox 3 browser or as a standalone application. Pencil is a cross-platform application and can work well on any platform that Mozilla Firefox 3 supports.