We have recently fixed some bugs in the syntax highlighting support for Textmate and Sublime Text as well as for vim.
Syntax highligting in Sublime Text
Textmate and Sublime Text used the same plugin which can be found on GitHub at https://github.com/dylan-lang/dylan.tmbundle.
Also, we’ve submitted a request for this plugin to be made available via Package Control for Sublime Text and hope that this is ready in the near future.
Syntax highlighting in vim
We extended the Dylan support of vim:
The files for vim can be found in https://github.com/dylan-lang/dylan-vim.
Patches and further improvements are welcome!