Web 2.0 has drastically shifted typical Web users from passive users to active developers. Web users share photos and videos, write blogs, and extend wiki pages. Yet end users need support to build their own applications on the Web. WEUP aims to provide the required tools for Web users to develop programmable artifacts on the Web. However, Web users have different domains of interest for development. Therefore, providing a one-off tool for all the Web users on the Web is not possible. WEUP provides a Web-based infrastructure for developing and sharing customizable EUP tools so that Web 2.0 communities can tailor them to create EUP integrated development environments according to their domain.