I am looking at a C++ project on OpenVMS.
How different is it from NIX development? Is it a bit like a peculiar UNIX version or LINUX distro?
Any peculiarities when it comes to memory management or threading etc? (I know FILE I/O is a bit different).
Are the C++ compilers a bit like older C++ versions on other platforms? (Less support for templates etc.)
Can I use bash, without touching DCL?
What about IDEs, debugging (gdb) source control etc? (It seams NetBeans are OK)
Can I work remotely with X-Windows? Will admin access be a problem?
OpenVMS might seem quite different if you've only developed with a Unix based derivative. Taking your questions one by one.
1) Memory management from C++ will feel the same. There is pthreads support. File I/O has more options, but many will feel foreign to you. The basics operate as you would expect including C++'s iostreams.
2) I don't think gcc is functional for VMS on Itanium. You will need to use HP's C++ compiler. It is a repackaging of an older version of the Intel C++ compiler. Don't expect support for c++-11 any time soon. Template support is good. The STL works.
3) There is an open source bash solution. You may be happier with DCL and some perl. Perl works on VMS.
4) No C++ IDEs that I know of.
5) X Windows should work.
6) Sysadmin access. Depends on what you want access to. VMS does have a rich access control mechanism and enables finer grained access to some parts of the system without resorting to a sudo like solution. Ask your sysadmin to get more details.