Actually I'm stripping out a bunch of stuff. I'm not using any DHCP, firewall, connection tracking, dropbear, etc. Trying to build a very small very specific image with just PHP and a tiny web browser. I'm still experimenting with it, but seem to have a stable image running for over 4 hours now. Just sitting in an endless loop in a PHP script running in the console. Sleeps for 10 mins, wakes up downloads a small webpage, prints the source to console and saves the source to file, then goes back to sleep for 10 mins. Running a 12MB OPENWRT image. RB751 still has 2.7MB free memory and 16MB free HD. I still think I have some room to shrink it even more.
I'm finding this fun, takes me back to the DOS days. I remember writing programs that had to fit in to a 64K source and 64k data segments, showing my age