I currently manage all my X10 home automation with MisterHouse which is a fantastic tool but is a bit on the heavyweight side. Plus you need to know a bit of Perl to take full advantage of it.
If you are looking for something simpler to use, you might want to consider HEYU.
HEYU provides a complete control of X10 devices (on, off, dim, bright, …)
and will let you send X10 commands directly from the command line.
A simple config file format will let you create aliases and plan the schedule of your X10 controlled appliances.
This schedule can then be saved in your CM11A memory (so that you don’t need to let your computer powered on to control your appliances).
So if you’re looking for something simple yet complete to control your X10 home automation, be sure to have a look at HEYU.