If you write dtsx in SQL Server 2005, often (if not always) you have to make them configurable, in particular if you need to deploy them in various environments (dev, test, staging and production).
Natively the SSMS produces a single-line xml file, so not very readable, but there is a little trick to format them automatically:
- open the dtsConfig file
- in the editor, right click and "View Data Grid"
- expand the grid and make a small modification of a value (for example, add and delete a space)
- save the file