Does anyone use RT-11?

Just as there were inquiries about using PDP-11 hardware, I thought that it might be helpful to know if anyone uses RT-11 and for what purpose. For myself, I have the addiction of fixing RT-11 bugs in the operating system as well as making enhancements. Ten years ago, I even produced most of the Y2K changes that were required for V05.04G of RT-11 for a customer who could not wait for Mentec. Eventually, I want to produce a set of Y9K changes to allow years up to 9999 to be used. Other enhancements include SL: and a new pseudo device driver, SB: (SymBolic device list device driver) which is similar to the VMS SNL (Symbolic Name List), but operates only on a device which supports a directory as does PATH for DOS. At one point it was named PH: for Path Handler, but SB: seems a better choice. Even more reasonable would be Symbolic device List or SL:, but SL: is already used by the Single Line editor (or the DOSKEY interface). Symbolic Debugger is also taken for SD: Lately, I mostly use Ersatz-11 and I have been making changes and enhancements to the HD: (Hypothetical Disk) device driver that John Wilson originally wrote in 1995. The challenge I set myself was to produce a VM(X).SYS equivalent that is: (a) Faster - about 3 times as fast (b) Higher capacity - a full 65536 blocks vs 8192 blocks (c) Smaller number of LOADed words in low memory (d) Support the command SET VM: [NO]WRITE plus a number of other useful features. Well, one idea led to another and other versions are also being tested which support 8 units and eventually 64 units (with monitors that have that support as well). If there is any interest, eventually a translation table similar to the one used by DU(X).SYS is possible. In addition, full 32 bit block number support will be done eventually which will allow 2 TeraByte disk drives. The other HD: related code that is also interesting is the ability to interface the HD: device directly from user code WITHOUT a device driver. So while the HD: is about twice as fast as DU(X).SYS when a device driver HD(X).SYS is used, the direct user interface (which avoids all the overhead of a system EMT call) is about twice as fast again. For this user interface, 32 bit blocks numbers are already possible. Under a Windows (YEK !! Double YEK) operating system or even just DOS, all disk access is completed before the HD: returns control to the RT-11 operating system. Consequently, no interrupts are required. I am not sure about Linux operation, but if anyone does know, please advise. Sincerely yours, Jerome Fine