Some programs are build for all cpu architectures within Linux - typically all of the i386 packages (e.g. rpms) will contain executables that you can copy across for use on these devices. If this does not work, you will need to get hold of the source code for the application. Try the openwrt sources for example...

Building with the default compiler

As these platforms have a 486 compatible chip, it should be possible to use your standard install of gcc. I have not tried this, but I suspect something along the lines of adding the flags -march=i486 -m32 to the compiler is required.

Building using the AMIT toolchain

If you have previously tried Building the firmware, or at least installed the cross compiler that comes with the source, you can use that. Normally running any configure programs to generate the Makefile, then adding the line include ../MGB100_GPL/Makefile.config to the top of the Makefile will suffice. This assumes that ‘‘../MGB100_GPL’ is the directory that contains the source code. Modify this to correct the path appropriately. I have successfully built ntpclient, ftpd-topfield and others this way.

see part of this thread too.

Software that is known to work using this method

ntp-client
ftpd-topfield
puppy