This excellent article by Stephen Shankland explains very clearly what SCO might, could, should do on Monday if IBM doesn't settle. Several attorneys give their opinions and SCO gives some hints. "If" seems silly to write. "When" they don't settle seem a better choice of words. So far, IBM shows no sign of wishing to settle.
The article mentions SCO possibly seeking a preliminary injunction. Here is 'Lectric Law Library's definition of what that is.
For a walk down memory lane, and because Darl McBride keeps calling Linux users pirates and using Napster as a metaphor, here is the preliminary injunction that was granted against Napster. You'll see that basically a preliminary injunction is what the judge orders to happen while the trial proceeds. If you can convince a judge that the person or entity you are suing, if allowed to continue unchecked, will harm you so badly by the time the trial can be heard that you could never be made whole, and that you have a case, then you may be granted a preliminary injunction.
More precisely, you are supposed to get a preliminary injunction if you can show a "(1) probability of success on the merits and a possibility of irreparable injury, or (2) serious questions going to the merits and the balance of hardships tipping sharply" in your favor. -- Chalk v. United States Dist. Ct., 840 F.2d 701, 704 (9th Cir. 1988).
If money can make you whole at the end of the trial, it's not normal to be granted a preliminary injunction. That is the problem SCO faces, that it may just have to wait for the trial to end before it can get any relief, if then, because money presumably can make them whole. That is, after all, what they are asking the court to give them, unlike the Napster situation, where the relief sought was more than money.
Or for another example, Sun won a preliminary injunction against Microsoft in 1998, to stop, or enjoin, Microsoft from shipping their products with an incompatible version of their Java software, the reasoning being that allowing MS to go forward would make it impossible for Sun to ever be made whole, because the deed would be done and undoable. Not that the injunction did Sun much good anyway. But that is an example to explain what kinds of things a judge can do with a preliminary injunction.
Another way to put it would be that the injunction is designed to make sure that winning your case won't be in name only and that the relief you seek will still be available to you at the end of the trial. This from Steven E. Shapiro's article "Preliminary Injunction Motions in Patent Litigation":
An injunction is "an order that is directed to a party, enforceable by contempt, and designed to accord or protect some or all of the substantive relief sought by a complaint in more than temporary fashion." [n2] A preliminary injunction is a provisional injunction issued pending the disposition of a litigation, [n3] the purpose of which is to "preserve the status quo and to protect the respective rights of the parties pending a determination on the merits." [n4] Sometimes a judge might require the party being sued to put up money in escrow so that there is a guarantee that the suing party will have something to take home with them, but that seems unlikely here, where it'd be hard to argue that IBM will run out of money before the case can be heard. Or ever. This, of course, is what makes them an appealing target for a lawsuit.
[n2] Gon v. First State Insurance Co., 871 F.2d 863, 865 (9th Cir.1989).
[n3] See Fed.R.Civ.P. § 65.
[n4] Cordis Corp. v. Medtronic, Inc., 835 F.2d 859, 863, 5 U.S.P.Q.2d 1118, 1121