The HTC Apache is a Windows Mobile 5.0 device, sold as the PPC-6700 by Sprint, and the XV6700 by Verizon Wireless and other US carriers.

The Apache is a Pocket PC PDA with smartphone capabilities.

The upgraded generation of the model is the HTC Mogul, also known as the HTC Titan, the PPC-6800, or the XV6800 from Verizon Wireless.

Reference: Section 5.4 of the Verizon XV6700 User Manual (expansion slot compatible with miniSD and MMC cards) Due to the popularity of the device there are many unofficial Operating System releases found on the Internet.

Most notably, Windows Mobile 6.5 Professional.