It may sound silly to try to put DOS executables online, but think about it: they are usually very small, very fast, and they can run on a wide variety of platforms. Of course there is a problem with security. I tried to overcome this by allowing download of NetDOS executables only from trusted URLs. And there are specific applications (like for an Intranet), where security is not so important and where executables are being downloaded from the server all the time. And you should also consider the fact that ALL programs that you download from the Internet, with the exception of Java applets, are executables: if you run them, you have already decided to trust their authors. In any case, executing programs is hazardous only in a single-user system, like plain DOS; if you are running some DOS emulator (like DOSEMU under Linux), it can be configured to be as secure as a Java virtual machine.
I chose the following MIME types for *.EXE and *.COM files:
application/x-netdos-exe and application/x-netdos-com.
Suggested file extensions on the server side are .netdos-exe and .netdos-com. A simple .exe or .com would be misleading, since normal DOS programs are not expected to be executed after download is completed.
You can try the NetDOS scheme by downloading several short (4KB) ASM demos from the NetDOS homepage (but only if you are online).