I presume if you have such a library, you have a network of servers and other computers that need to be backed up. So, your broader question really relates to doing that with the requirement that it be able to handle the SpectraLogic. Also, since you are posting on the linux server forum, it would seem that's the platform you will be using.
If I were doing it, I would use amanda.
http://www.linuxquestions.org/bookmarks/tags/amanda
amanda has the advantage of being very unix/linux like in that it relies on and plugs into native utilities and formats. I've found it to be very robust and reliable.
You can get an overview from the chapter in the backup book referenced in the bookmarks above. Then for a quick start, use the entry by that title in the wiki:
http://wiki.zmanda.com/index.php/Quick_start
Basically, you'll use mtx <http://mtx.opensource-sw.net/> to run the library. Once you have drivers installed, mtx working from the command line, and mt working from the command line to access the tape drives, you can use the amanda glue script chg-zd-mtx.
There will be a little bit of a learning curve, but that's true of any software with these capabilities. One thing that takes a little getting used to is the amanda backup strategy. Amanda plans out the sequence of fulls and incrementals and evens the backup load over the backup cycle (say, a week). Each disk list entry (DLE) in your configuration is guaranteed at least one full backup during the cycle, and will get incrementals of some level on all other days. So you don't have a huge burst of backup activity on one day using multiple tapes and then a trickle on the other days barely using much of the tapes for those days. Instead, you have a steady flow using about the same amount of tape every day (and network demand, and time). This is something I really like. It also adjusts automatically to changes in disk usage over time.
