To compile Horus, you need to have either the complete source distribution, or a binary distribution for the configuration you want. Assuming that your Horus root directory is called Horus, and that the configuration that you are trying to build is called "sun4", enter the direction horus/conf/sun4. Horus uses a compiled-in name for a shared directory through which it can find the address of the name server, among others. When using the binary distribution, you need to override this directory, by setting the environment variable MUTS_ETC. Typically, you set it to the "etc" subdirectory of the main Horus directory:
setenv MUTS_ETC $HOME/horus/etc
If you have a source distribution and this is the first time (or the first time since you made a change to this configuration), first invoke "../../src/tools/config". This will create a Makefile for you under the name "Horus.mk", which builds a library that you link with Horus applications. After that, run "make -f Horus.mk".
Once you have a library, you can make the standard Horus demonstration programs by just running "make".