Porteus

I was wondering how to create a custom startup script, I want a few things to startup on boot if possible.

You can also customize your startup through the Porteus Settings Center, which uses the 'sysvinit' style, so you can add multiple scripts to start at various runlevels across mutiple modules (you don't want to use rc.local in those cases, as differing copies would be overwritten by other modules/rootcopy/saved changes). If you're just looking to have applications start up inside your desktop environment, that can be handled as well, but each desktop environment is a little different.