I'm currently building my own pack, though it doesn't have any particular focus, mostly just mods my friends and I find potentially fun/interesting and want to try out. Sort of like a Horizons pack but bigger, and I plan to update it relatively often. I just set it up on my test server this weekend, working OK *so far*, only one server crash to date (excluding crashes from 2 mods whose latest builds crash on servers but not clients.) Need to tweak configs and get modpack distribution permissions from some of the mods still. Whew...making a mod pack is a lot of work!