As an UI/UX designer, drawing a mockup isn't stranger thing for me. On software development, mockup is important thing before writing code. Before i use Pencil, i drawing mockup on Inkscape (because i am also Inkscape user too). I think it's a quite difficult to drawing mockup on Inkscape because i must drawing a mockup from scratch. After a friend told me about Pencil, i think this software can meet my requirements to drawing mockup. Pencil providing mockup collections from desktop through mobile. It's very fun that we can drag and drop from this mockup collections.

An overview about Pencil. Pencil is built for the purpose of providing a free and open-source GUI prototyping tool that people can easily install and use to create mockups in popular desktop platforms. The code is hosted in github: https://github.com/prikhi/pencil/. On openSUSE repository, Pencil can be found at https://software.opensuse.org/package/pencil.The latest stable version of Pencil is 2.0.5 and the next release will be 3.0.0