Format your text bold, italic or underlined
Insert Images, files and links to websites
Links and mail addresses are recognized automatically
Spell Check on Linux
Backup to zip archive
Word Clouds with most often used words and tags
Export the journal to PDF, HTML, Latex or plain text
The data is stored in plain text files, no database is needed
Translated into more than 20 languages
As impressive as the features sounded, I just liked the look of it; it's very uncluttered and seemed like it would be easy to use. Which it definitely is. The download went so fast I didn't realize it was done, and the installation was a breeze (completely virus-free, too, when I scanned it.) When I started it up it came with instructions preloaded in the first work area, but you can delete these easily.
The program is calendar-based, which means you work under the date of your choosing (handy if you're looking for a virtual diary or task manager.) You can input text and images in the work area, which I really like a lot, and do things like bullets and titles and so forth. Here's a screenshot of my first entry (click on any image to see larger version):
There aren't a huge amount of options; just enough for a working writer or someone who wants to organize their info. On the downside you can't print direct from RedNotebook, but you can easily export to .pdf, text file, html, etc., which is the next best thing. I really like that you can export a range of as much data as you want, anywhere from one day to all the days stored in the program.
Another feature I thought was truly neat was a statistics option, which pops up in a little window to analyze your data. Here's what it looks like:
It not only tells you how many words, lines and letters you've typed on a selected day, it keeps running totals for your entire wordcount, distinct words, the days you've edited, the days between your first and last entry, the average number of words you're writing and what percentage has been edited. If you use RedNotebook for writing or as a mirror depository for your daily work, the statistics make it almost the perfect virtual notebook for monitoring your progress on a project (extremely handy for something like NaNoWriMo.)
This would also be an excellent program to keep as a drafting area and/or a mirror archive for blog content, daily/weekly/monthly to-do lists, reminders and schedules. Another option would be to use it as a daily ledger to track your expenses, especially as at the end of each month you could export your data to a .pdf, print it out and have a printed version to serve as your ledger.
RedNotebook is 100% free and available to download for Windows, Mac OS X and Linux, plus a bunch of other distributions (which you can read about here.) For those of you who are on the go, there's a portable version, too.