"It's about time this happened, and very interesting that IBM has decided to broaden this out," said James Governor, principal analyst at Redmonk Consulting.
"IBM was in the firing line and quite frankly it reassured a lot of enterprise customers that they should proceed with their plan. IBM got hit by a lot of legal costs and now it's their turn to go on the offensive."
Microsoft's subpoena asks for all information on any agreements between Microsoft and SCO, as well as its business strategy regarding Linux.
It also demands "all communications between Microsoft and SCO since 28 June 2002 including, but not limited to, [SCO chairman and chief executive] Darl McBride's communication in May of 2003 with [Microsoft chief executive] Steve Ballmer regarding SCO's rights to the Unix operating system".
"This sounds very interesting indeed," said Teresa Jones, senior research analyst at the Butler Group. "I would not be at all surprised if IBM has problems getting this information."
Microsoft has an internal policy against archiving emails, but the Sarbanes-Oxley Act, introduced in the wake of the Enron debacle, requires email retention for seven years.
The Sun Microsystems subpoena includes similarly precise requests, including details of the meeting between Darl McBride and Scott McNealy, Sun's chairman and chief executive, in May 2003 regarding SCO's rights to the Unix operating system and any joint business plans between the two companies.
"The precise nature of some of these requests is very interesting, they must know exactly what they are looking for," said Gary Barnett, research director at Ovum.
"IBM has been extremely precise in every move than its taken; it's been incredibly instructive in showing how these things should be done. Many of SCO's requests have been vague fishing nets compared to IBM's precision."
He continued that he was getting a sense that the case was entering a new gear in the pace of the case. However the case may drag on, despite SCO " scraping the bottom of the barrel by now."
The Baystar Capital subpoena demands any communication via email, instant messaging, letter, IRC and even telex between Baystar and Microsoft regarding SCO, IBM or the SCO v IBM litigation, as well as all documents regarding Baystar's investment in SCO.
This could answer a long-running question as to the extent to which Baystar and Microsoft enjoyed a financial relationship, and whether there was any link between this and Baystar's funding of SCO during the case.
The HP subpoena is mainly concerned with the company's Unix activities, seeking all documents relating to the origin of any Unix source code and any royalties.
Could be used for everything from search-and-rescue robots to wearable tech
Don't require the rare material being mined from the mountains of South America
IBM hopes that its new tool will avoid bias in artificial intelligence
Found by calculating the strength of the material deep inside the crust of neutron stars