DL Pager functions quite well on different platforms, and the increase in performance, especially on Windows, can be astounding. In one customer benchmark, a job which took eight hours to compose on a VAX 3100 was completed in under ten minutes on a 300 MHz laptop running Pager NT.
Aside from having to build the ancillary binary files (.bst, .lbr, .bfm, .inx), you can easily move DL Pager files across systems. Here at Datalogics, we routinely develop applications on all platforms and move them around without having to make any markup, format or PKC file changes; DL Pager can automatically translate file names and path syntax, and with a little planning the process is almost transparent.
Unfortunately, neither Windows nor Solaris can match the capabilities of OpenVMS' Digital Command Language and other OpenVMS "built-in" features, such as batch queues, file versions and the comprehensive SORT/MERGE utility. You'll have to write your own scripts and utilities to implement your site-specific requirements. On Windows, you can use DL Publisher and DL Queue to emulate basic OpenVMS batch functionality.
Datalogics can help you evaluate your needs and provide migration planning and implementation services.