Abonner for at downloade
CO-OP Map Pack (Part 1)

Lots of co-op maps. Originally uploaded for WorkshopDL for a (now defunct) server, but you can subscribe and use if you want.

Maps:

coop_rebel_fix
coop_sd_zombie-city_b1
gm_defendtheemerald (map I made long ago)
gm_mczombies_thesequel_v1 (another map I made long ago)
gm_mczombies_v2 (favorite map I did long ago)
gm_park_night (an edit of that old themepark map. Has a zombie invasion button in the middle)
js_coop_blueberry_ob_v1_d
js_coop_combine2_sg_b4
js_coop_killer_lost_final
js_coop_powerworks_v2
js_coop_shore
js_coop_teleport_sg_zb3
js_coop_thunder
sg_coop_lockdown_b3
sg_coop_overwatch_b4
sg_coop_resistance_b1
tbr_coop_thousand_antlions_v3b

If any author of these maps wants me to remove it, I will with no questions asked.
All credit goes to the original authors.