I probably shoud be clearer. The apparent difference that I am asking about between MSDOS and Linux is that in MSDOS, you can execute a command that is not in the path simply by typing the command name, so long as that command (an exe file, say) resides in the current directory.
For example, if apache (or any program) for windows or dos was installed in C:\Apache\ and the file to run it was "apache.exe" (I have no idea what it is in reality, but that doesn't matter here), I could run that program simply by typing "apache" from the prompt at C:\Apache, regardless of whether that directory was in the path.
From my little experience with installing apache in Linux described above, it seems that this does not hold true for Linux. In other words, even if the executable file is in the current directory, I still have to specify "./" first if I want to run it.
Am I correct?