Here is a list of PHP Editors (but all of them should handle KiXtart as well since it is all pure text, but may not have specific functionality geared towards KiXtart)

Currently 111 Editors listed. Allows filtering by Platform and License.
 
The Linux Consultancy Guide to PHP Editors

 Note: This link is no longer being updated as of at least March 2006 but is still on line

Edited by NTDOC (2006-03-13 09:25 AM)