Features:

.Mac Sync:
With this feature you can always have the same preferences if you work on different computers. It uploads the Smultron preference-file to /Documents/Smultron Preferences on your iDisk and downloads it from there if you choose "Download Preferences from your iDisk" and sets the current preferences accordingly.

Command-line utility:
Install it through the Help-menu (note that if you choose to install it directly you have to authenticate with an administrators username and password twice; once for the utility and once for its man page). With smultron (the name of the utility) you can start the application Smultron by just writing "smultron" in the Terminal with no options. If you write something after "smultron" it considers that to be the path to the file; if you don't specify a full path it adds the current working directory to what you write. If it can't find the file, it first creates it and then opens it. Some examples: "smultron" - opens the application, "smultron foo" - opens foo from the current directory in the application, "smultron /Users/steve/foo" - opens foo from /Users/steve in the application. For more information write "man smultron" in the Terminal.

Services:
If you choose Services from "application"-menu you can make Smultron open the currently selected file, insert the selection into the current document or create a new document with the current selection. (Note that you need to log out and then log in at least once before this feature works.)

Projects:
You can save the paths to all open documents (note though that it doesn't include new unsaved files) as a special file (with the extension .smlp) and open all those documents in just one step, if you e.g. are working on a project. For Smultron to recognise the file as a project, the extension needs to be smlp. Note also that if there are other documents open they will remain open and the new documents will just be added.

Advanced Find:
Multi-document search and replace with the option to use regular expressions.

Show Invisible Characters:
Shows a symbol for characters that are usually not seen, i.e. space, tab and new-line.

Drag-and-drop of files into the documents list:
You can drag-and-drop one file or several files into the document list and SMultron opens them.

Grab text to scroll:
If you press the option (alternate) key and drag with the mouse you scroll the text.

Print settings:
When you choose Print... you can choose Smultron in the pop-up menu and choose which font to use. You can also choose if you want to print the header and if you only want to print the current selection. It is also possible to set the smallest margin you want to use.

Code snippets:
With the code snippets drawer you can temporarily or permanently store snippets of code that you will use again. Drag text to the drawer to create a new or add text to an existing, or press the + button to create a blank. Press the - button to remove a snippet. The code snippets are saved in your preference file but if you want to export it to another computer you can choose Export Code Snippets... from the File menu or just move the preference file (it is located at <your home folder>/Library/Preferences/org.smultron.Smultron.plist).

Find Drawer:
Here you search for all occurrences of a string in the current document. To go to an occurrence just select it.

Open Hidden...:
With this you can see all the files even the ones that the system usually hides.

Preview:
With this you can preview the HTML in the current document.

Save A Copy As...:
Save a (backup) copy at a location without affecting your current file.

Remove Needless Whitespace:
Removes any possible spaces or tabs after the text and before the line break.

Entab & detab:
Replace tabs in the selected text with spaces or vice-versa.

Shift left & right:
Remove tabs and spaces to shift to selected text to the left or insert tabs to move it to the right.

You can navigate between different documents this way:
Press Command and Option and Up-Arrow to select the document above in the list, and Command and Option and Down-Arrow to select the one below.
You can also select the first ten documents in the list by pressing Command and a number from 1 to 0.

Line numbers:
If you don't want to show the line numbers choose Hide Line Numbers in the toolbar or in the View-menu. Or you can set the Preferences to not show line numbers for new documents.

Syntax colours:
If you don't want to show the syntax colours choose Hide Syntax Colours in the toolbar or in the View-menu. Or you can set the Preferences to not show syntax colours for new documents.

Line wrap:
If you don't want the lines to wrap at the end of the window choose Don't Line Wrap in the toolbar or in the Text-menu. Or you can set the Preferences to not line wrap new documents.

Status Bar:
If you don't want to show the Status Bar choose Hide Status Bar in the View-menu or if you just want to not show a particular information set the Preferences to your wish.

Close Tag:
This tries to find the correct tag to close by calculating the number of tags that has been closed and opened (skipping tags like <br> and <hr />) so it will find the last tag that was opened but not closed. After it has found the correct one it insets the closing tag adding a / to the opening tag e.g. </head>. Note that this feature only works with tags surrounded by < and >.