Joined: 06 Jun 2008 Posts: 8217 Location: Dubuque, Iowa, USA
Which DOS? Which Unix (Sun, HPUX, AIX, LINUX, etc)? What do you mean by compatibility? Which mainframes? Performance compatibility means what? FTP is an industry standard and there are IETF standards for FTP so all FTPs are somewhat compatible.
Basically, you need to revisit the entire post and be more specific and detailed about what you're trying to accomplish. A post like this is rightly ignored since you obviously want either several hundred mainframe manuals regurgitated to you or you're wanting something you're not telling us.
Joined: 23 Nov 2006 Posts: 19270 Location: Inside the Matrix
If you explain what you are interested in or what you need to do, someone may have a suggestion (i've been a sysadmin/database admin on the mainframe, multiple unix systems, and win-based systems - others here have even more experience).