Many OS/2 SAAREXX programs work almost as is under WindowsNT ooRexx, the RexxUtil functions are similar, the WindowsNT CMD shell is similar, and the RxSock interface is almost identical. Some OS/2 RexxUtil functions are not yet or not more supported under WindowsNT, e.g. SysGetMessage, SysProcessType, and SysQueryProcessCodePage.
Scripts I've tested under W2K after renaming *.cmd to *.rex include popstop2.cmd, dir2html.cmd, and sitemap.cmd.
Unfortunately ooRexx doesn't come with RxFTP.dll, but it offers the RxFTP.cls class. I've created a new ftpsynch.rex based on ftpsynch.cmd for ooRexx, for details see ftpsynch.htm.