The 90° angled 6-pin, 100mil header is the PDI programming and debugging header for the ATxmega128B1.
The XMEGA-B1 Xplained kit also has a USB 2.0 mini B connector.
The XMEGA-B1 Xplained kit has four 10-pin, 100mil headers. Two headers have a fixed communication interface (J1 and J4). One header has analog functionality (J2), and the last header (J3) has general purpose digital I/O.
For the location of the respective headers, refer to Figure 1.