gCSVedit is now a free/libre software (GPLv3+ license) and is hosted on GitHub.
Other delimiter-separated values (DSV) files are supported, not just comma-separated values (CSV) files, but “CSV” is more commonly used to refer to that kind of file.
Why developing a new application for editing CSV files?
A general-purpose text editor like gedit is not the best choice either, because the columns are not aligned. There are some plugins for Eclipse or other IDEs available, but launching and using a complete IDE just to view or edit a CSV file is not user-friendly either.
The best is a specialized application, to do just one thing but do it well. With a user interface that goes straight to the point.
Spreadsheet or text editor?
With a text editor, all characters are visible, including the delimiters. We have thus a greater control. When writing a script to extract the data contained in the file, it’s important to view every character in case of problems (like an extra separator in the data but not for the column titles).
Also, some software that generate CSV files sometimes also include an header, i.e. some text before the actual CSV fields. With a text editor, the header can be shown in a natural way.
Hopefully in the future it’ll be possible to re-use more code of gedit, to have a decent text editor (although gCSVedit is already completely usable).
So, nothing revolutionary here, it’s a small project. But I think it can bring a better usability. Comments, questions?
PS: to show where are the real spaces (those present in the file, not those added for the alignment), I’ve already contributed to GtkSourceView and GTK+. There will maybe be more contributions in the future, for example to implement a utility to insert virtual spaces, i.e. the text editor should behave as if the added spaces didn’t exist. Or, finally implement rectangular selection in GtkTextView.
Edit: gCSVedit has moved several times where it was hosted, I’ve updated the above URLs.