The AXIOM Beta has 2 medium speed IO interfaces to be used with "shields".
2x10 GPIO banks as LED indicators plus two power LEDs. 4 LVDS pairs routed to external connectors JP1/JP2 (2 LVDS plus one GND each).
V0.2:
http://files.apertus.org/HARDWARE/AXIOM/BETA/SHIELDS/axiom_beta_shield_debug_v0.2.brd
http://files.apertus.org/HARDWARE/AXIOM/BETA/SHIELDS/axiom_beta_shield_debug_v0.2.sch
V0.1:
BOM: https://octopart.com/bom-tool/gFGhZyGC