You could have downloaded ThemeEditor 1.4 from our software library for free. This free software was originally designed by Dries Buytaert. The most popular versions of the program 1.4 and 1.0. ThemeEditor lies within Desktop Tools, more precisely Themes. ThemeEditor.exe is the frequent file name to indicate this program's installer.
From the developer:
There is now a semi-working D7 version committed to the Repo. While it's not ready for a dev version yet it can be downloaded via GIT and tested. Any testing or help on development would be much appreciated. Theme Editor offers an editing interface for Drupal themes allowing users to edit themes from within Drupal. No more need for server/ftp access!
You may want to check out more software, such as Delphi IDE Theme Editor or Carbide.ui Series 40 Theme Edition, which might be similar to ThemeEditor.