Jan,

UL is ultralight, originally from:
http://ultralight.caltech.edu/web-site/ultralight/workgroups/network/Kernel/kernel.html

UL is not associated with Oracle or unbreakable linux in any way.  

We have been continuing the work of the UL team by releasing kernel rpms using UL specs with newer kernel sources and a few config changes for x86_64 file servers. 

We at mwt2 have taken it upon ourselves (as I am sure have many others)  to build our own kernels to use some of the newer kernel features for virtio on KVM for example as well as get better IO performance with kernel config option CONFIG_PREEMPT_NONE=y.

-Nate

On May 26, 2011, at 9:41 AM, Jan Kundrát wrote:

> On 05/26/11 01:48, Nathan Yehle wrote:
>> I have rebuilt 2.6.39-UL1 using the Ultralight RPM specs to create
>> this rpm for use with Scientific Computing Servers at MWT2.org.
> 
> Hi, is that the "unbreakable Linux" kernel from Oracle, or some other
> "UL" thing? (I'm not familiar with "Ultralight" patchset, and even
> Google won't tell much, hence this question).
> 
> Cheers,
> Jan
>