Xuheki is a fully featured email (IMAP) client for the Web. It looks and feels like an application rather than a Web site. It is fast, clean, and features no page reloads. It supports multiple users per installment, multiple IMAP servers per user, and multiple folders per IMAP server. It also supports text or HTML email, attachments, inline images, printing, and more. It has an "AJAX" interface that could compete with desktop-based mail user agents.
Yii is a high-performance, component-based PHP framework for developing large-scale Web applications. Yii comes with a full stack of features needed by Web application development. It is written in a strict OOP style and is easy to learn with its detailed tutorials. Its highly reusable components allows one to rapidly build up a Web application that is efficient as well as robust.
Yoxel SW is an adaptive project management solution allowing you to maintain a continuous feedback loop with your customers while collaboratively planning and implementing development iterations. It includes a request/bug tracker, release manager, customer portal, and knowledge/Q&A/FAQ management system.