Programming in Ruby Using SciTE - Windows Issues and Other Tips
Couple of comments(by Mihail and Jonathan) on my earlier post about programming in Ruby using SciTE editor brought this to my notice: When using SciTE to develop Ruby programs on Windows platform, there are a few issues that one needs to be aware of.
Adding a Menu Entry to Invoke irb Command
If you use the Ruby interactive shell frequently and don't want to type seven characters each time you want to invoke it, then create a menu entry/keyboard shortcut for it. To do this, open the Ruby properties file by selecting Options -> Open ruby.properties menu item and search for Windows-specific settings(PLAT_WIN section).

Add the following lines in that section:
command.name.0.*.rb=irb
command.0.*.rb=irb.bat
command.is.filter.0.*.rb=1
command.0.subsystem.*.rb=1
Use another number in place of '0' if you have already bound it to something else. The first line(command.name.0) defines the name to be used in as the menu entry. The second line(command.0) defines the command to be invoked when this menu entry is selected. A value of '1' in the third line(command.is.filter.0) indicates to SciTE that the command may modify the contents of the current file(file is reloaded based on the value of load.on.activate setting).
The section in the properties file should look like this:

You can now invoke irb from Tools -> irb or by using Ctrl-0 key command. Note that this menu item will be visible only when editing .rb files. Ctrl-F6 will switch you between the file pane and the output pane.
What about GNU/Linux?
You can add a similar section in PLAT_GTK section if you are using SciTE on GNU/Linux platform, but use irb in the second line in place of irb.bat:
command.name.0.*.rb=irb
command.0.*.rb=irb
command.is.filter.0.*.rb=1
command.0.subsystem.*.rb=1
Add menu items to other frequently used commands in the same way(even links to help documents). For more information, refer to help document available from Help -> SciTE Help.