What is "Skimo"?
Skimo stands for ski mountaineering.  In essence, it involves skiing uphill using specialized bindings, boots, and "skins", and then transfer to "downhill" mode on your equipment for a regular ski descent.  Sometimes there's also a "bootpack" where you carry your skis and hike uphill in your boots.  Skimo could consist of a technical mountain ascent and descent with just a few friends in the backcountry, or a race setting at a resort with a few hundred participants.
Skimo has been growing as large numbers of of cyclists, runners, and others find it a great way to stay in shape in the winter,.  They quickly realize it might be more fun than even their main summertime sport!  For those just trying it out, a few great articles explaining some of the overviews are here and here.

Doesn't that just sound like backcountry touring?
Well, sort of, yes.  The lexicon becomes a bit trivial and confusing, but here's my take:  backcountry skiing is typically more focused on the quality of the ski descent, enjoyment of being away from the crowds, adventure of exploring more remote terrain, and the added physical enjoyment of earning your turns.  Mostly Type 1 Fun.  Skimo is a little more "objective" focused rather than fun, either on ascending/descending as quick as you can on a race course, or on climbing a specific peak.  Skimo is as much about the ascent and the physical workout as it is about the descent.  So more Type 2 Fun.  It could also be described as the combination of backcountry skiing and mountaineering.
Really though, labels are dumb, the English language is confusing, and we want people to feel comfortable coming out and having some fun in the snow no matter if you call yourself a "skimo racer" or a "backcountry skier".

I'm not even a skier; I ride a splitboard!  Can I come out and race?
Of course!  Splitboarders are definitely welcome.  While everyone is welcome in the "Elite" category, we've made a separate "Heavy Mettle" division for splitboarders and those skiers using heavier touring gear, not race specific equipment.  Any ski with frame bindings (Marker Tour F12, Salomon Guardian, Fritschi Freeride, etc) qualifies for the Heavy Mettle Division if you so wish (as opposed to a tech binding like a Dynafit or Plum brand).

How technical is the downhill portion of the race?  How good of a skier do I need to be?
Each racer differs, so take a look at the specific race page, but in general skiers should feel comfortable navigating expert and off-piste terrain at a ski resort.  But don't feel as if you have to ski downhill at breakneck speed; a lot more time can be gained or lost on the uphill than the downhill!

How long is a race typically?  How much elevation gain are we talking about?
Each race has two categories, an Elite category and a Recreational category.  The Elite category is going to be tough!  Elevation gain will be around 4k-5k' and last maybe 2-3 hours with a cutoff around 4 hours.  The Recreational category will be a shortened course with around 2k or so typically and last 1-3 hours.

What gear do I need?
Each race page has a list of required equipment along with suggested gear based on weather.  In general, the races require a ski or snowboard setup that is capable of uphill/downhill travel (skis, skins, bindings, boots, poles), a helmet, a pack capable of carrying your skis, and proper clothing layering.

This gear is really expensive! How can I get into the sport without breaking the bank?
We get it, this stuff can get expensive. Some people will be using highly specialized race gear, but feel free to come out with what you have. If you tour already, your setup would work to come out and have some fun. As you progress, get faster, and want to get on some better gear, there some options for you. We have a Gear Swap forum for people to buy/sell/trade, and there’s always end of the season deals as retailers are switching stock out. It’s easier on the wallet to upgrade a few pieces at a time rather than trying to buy an entire new setup all at once.

This is winter after all.  What if weather is really bad?
Mother Nature is pretty great, but sometimes she doesn't care that we all want to race on the weekend and doesn't play along.  Racers should prepare their clothing and gear for a variety of inclimate weather possibilities, as we will do our best to hold the race even if weather is rough.  However, we reserve the right to delay, alter, or cancel the race due to snow, weather, or safety concerns.  But we'll really try not to do that.

My partner/friends want to come watch and heckle me.  Is it spectator friendly?
Yes!  The courses explore all over the different mountains with different transitions, bootpacks, uphills, and downhills.  Your friends and family can come out to different parts of the course and cheer you on, while heckling your opponents.