The original intellistar was a joint effort. The specialized PCI boards were designed by WindRiver and they also wrote the firmware for those boards. The FreeBSD device driver was also developed by wind river.
The rest of it was done internally. The actual off the shelf hardware components plus O/S (FreeBSD 4.x) was chosen by the engineering group. As a result, TWC hired John H Baldwin (
jhb@freebsd.org) to ensure FreeBSD could be used and to be able to make any kernel mods necessary. Over time, bugs in the kernel were found (including a very old scheduler bug) and quashed by jhb. John was the MP tech lead of FreeBSD at the time. (FreeBSD was chosen due to issues with the Linux VM at the time, and also because RedHat was mandated if Linux were to be used. Back in that time, gcc 2.96 was released by redhat and was a train wreck. Multithreaded programs didn't work initially with that compiler, for instance).
The rendering engine and all the other high level software was written internally.
For the I2HD things went differently. It started out the same -- outsource the hardware, insource everything else. The problem was that the new world of HD was much more complex and it proved to be too difficult for the outsource partner. The I2 project was in big trouble as the partner had effectively failed. Out of the ashes of that effort, TWC decided to create a hardware engineering department and in-source the hardware engineering of the boards. The staff has very talented hardware designers and was augmented by equally talented firmware designers (who still work there today). It was managed totally in house. There ended up being 2 boards and a daughter card to make the I2HD work. The two main boards are PCIe boards and are very complicated. There are several instances of embedded linux running across the boards.
Again, the software was developed in-house. The new renderer was purchased from a 3rd party and integrated into the system (VizRT). The device driver was also done in house. The high level software is written in C#/F# running on Windows Embedded Standard (due to business requirements not present for I1).
The entire I2HD project was done with in-house engineering talent in the end after a failed 1st start.
As a side note, the "I2 alpha" that people refer to @ cablevision NY is not a Star at all. Just a random morsel of inside information to boggle your minds.