CORPS also stands for "Complete, Omniversal Role Playing System." It is, as the name suggests, an RPG (Roleplaying game) from BTRC (Blacksburg Tactical Research Center) similar to GURPS. Not only are the names similar, but some of the design ideologies are as well (although the game mechanics themselves are quiet different.
Like many RPGs of its type, character generation in CORPS is based on character points (in this case, two mutually-incompatible pools, one for attributes and one for skills). Attributes are Strength,Agility,Awareness.Will,Health, and Power. (Note the lack of Intelligence--Awareness fills that role to some degree, but a highly-skilled person could still have low Awareness and be smart, but have no common sense). Skills are organized in a tree structure--for instance, "Projectile Weapons" is a primary skill, "Pistols" is a secondary skill under it, and "9mm semiautomatic" might well be a tertiary skill. The GM is encouraged to modify the given skill trees, or simply create his own. Attribute and Skill points may also be used to purchase advantages, as in many systems, and taking disadvantages gains you more points, as expected.
Task resolution is rather unconventional. Attributes and Skills have numbers associated with them, usually in the range 1-10. (Secondary and Tertiary skills add to the primary--if you have 4 in Projectile Weapons, 2 in Pistols, and 1 in 9mm semiautomatics, you'd have a total skill of 7 when firing a Glock 17). However, you don't try to roll under this value on a d10, or roll a die and add the number. Rather, if the skill value is greater than a GM-defined (or system-defined, in some cases) "Difficulty", you automatically succeed, no die roll needed. If the difficulty is 6 or more greater than your skill, you are simply not able to accomplish the task--again, no die roll needed. Otherwise, you roll 1d10, and try to roll under a target value of 11, minus 2 for each point of difference between the difficulty and your skill (or attribute, or whatever). This sounds absolutely insane at first, and indeed does take some getting used to. However, you'll quickly learn your chances at succeeding at a task with a given difference (or just cheat and look at the table in the rules), and quite often you don't even have to bother--you know at a glance whether a task is trivial for a given character or totally out of his league. The biggest problem is graininess--there's only 6 levels between automatic success and automatic failure. I'm not really sure why the designer chose to do this, rather than alter the range of skill values, and use a straight -1 to target number per level of difference. Nevertheless, once you get past the initial "This is weird," the system works.
Combat is quite realistic and deadly. It also has a bit more complexity than it needs. Weapons have a damage value, which serves as both an impairment (penalty) to the body part hit, and as a chance of death, dismemberment, or other nasty effects. However, this value is modified in different, complex ways for different purposes, and depending on where the attack hit. You'll definitely need to re-read the damage rules several times before you're comfortable.
Most of the rest of the system is fairly straightforward, with the exception of supernatural powers. This takes a very different approach from other power-design systems (e.g. Champions) in that you use Skill points to buy the ability to use a particular power (whether this be the ability to pick locks with your mind, or cast fireball spells), and the effectiveness is based on your Power attribute. It took me many times reading this chapter before I could make any powers, and I'm still not entirely comfortable. I guess I'm too used to the buy-your-level-in-each-superpower systems.
One of the interesting things about CORPS is that it's available in PDF form (as well as hardcover form) from various online vendors. In addition, there are some supplements available, including VDS which is a vehicle creation system rather similar to GURPS Vehicles. You can also download "CORPS in a nutshell" from BTRC's site (www.btrc.net). This is a greatly-abbreviated, but free, version of the CORPS rules. It's a nice thing to pass out to players to use as a reference, and also gives you some idea of how the system works (a much better idea than you'd get from reading this writeup).