Free notifier software for linux

Mail Notifier provides an E-mail Notifier for POP3 accounts.

KGmailNotifier is a gmail notifier applet written for KDE using Python and PyKDE/PyQt.
When new mail has arrived in your inbox a small window will popup, showing author and subject of the newest mail. The underlined link (in blue) will take you straight to your inbox with your preferred browser.
KGmailNotifier is greatly inspired by the gmail notifier that can be found here: http://gmail-notify.sourceforge.net.
It also provides some additional features such as acoustic notification and support for LEDs on notebooks and multimedia keyboards.
KGmailNotifier uses the gmailatom library written by Juan Grande for the original Gmail-Notifier at Sourceforge.
Bug reports, critic, compliments, suggestions etc. are highly welcome.
Enhancements:
- Fixed an encoding bug when username or password contain special characters
- Added more languages

Tiny Tiny RSS Notifier is a notifier for your custom install of Tiny Tiny RSS.

Yahoo! Mail Notifier is an extension which notifies you when new messages arrive in your Yahoo mailbox.
Notification options include: customizable sound, notification alert, status bar and toolbar icon.
Also allows the user to map different mouse buttons to open Yahoo Mail in different tabs,windows,etc.
System requirements:
- Firefox 0.9.x - 3.0a3 ALL
- Mozilla 1.7 - 1.8 ALL
- SeaMonkey 1.0 - 1.5a ALL
Version restrictions:
1. The extension uses the Yahoo! Companion feed to check for new mail so only new messages received since last viewing your Yahoo Mailbox will be counted as new.
2. On some accounts, Yahoo! never updates the companion feed page when new mail arrives (you never see new mail notifications). This is a bug with your Yahoo account so contact Yahoo to have it fixed. If you dont get new mail notification when installing Yahoos official toolbar (toolbar.yahoo.com), then you are experiencing this problem.
3. Only the username marked as default will be checked for new mail. The extension can only check for mail if the user remains logged in. Logging out on a Yahoo page while the extension is actively checking will cause the extension to log back in to the default userss account the next time it checks for email. This is also true if you have sinced logged into another Yahoo account on a Yahoo page. This is done to prevent the extension from getting into a weird state where it thinks one user is logged in when in fact another user is. This will be fixed more thoroughly when multi-user support is added. If you dont want this to occur, use the extensions "log out" command instead of logging out on the Yahoo page which will log the default user out and stop checking for new mail.
4. Choosing a sound file to play on new mail has been reported to not work on Macs. The default sound is said to work. I dont have a Mac so I cant test this.
5. Im told that installing this extension in FreeBSD Firefox causes Firefox to crash. Im unable to test this as I dont have FreeBSD. Generally though all browser crashes should be reported to Mozilla since this is extension should be incapable of crashing the browser unless the browser is buggy.

GmNotify is a tray applet that notifies you of new messages from Gmail and provides an easy mechanism to get to them.

GmNotify will run in Gnome, KDE, and XFCE. I know, there are already a number of programs out there that provide this functionality. However, they all have limitations Ive tried to address here.

Smart notification placement
The notification popups will automatically be placed with the tray icon, much the same way Update Notifier does. Note: This only works on horizontal panels for now.

Multiple account support
GmNotify will have the ability to check multiple Gmail accounts a once.

No Gmail feed
Originally GmNotify used Gmails ATOM feed to get updates. This limits GmNotify to reporting on only 20 messages at once (not that you should actually display more than 5) and, more importantly, doesnt give you automatic label support (see below). GmNotify actually logins into Gmail the same way your browser would.

Label support
Labels will be fully supported before v1.0 so you can check more than just your Inbox. Also, all of your labels will be automatically imported, so theres no need to explicitly define them.

Proxy support
Those of you behind a web proxy will be covered.

Automatic login to Gmail
When you double click the tray icon youll go right to your Inbox. Simple, but convenient feature.

Automatic composer
This is another simple but nice to have feature. When you click on the senders name in the notification box you will be brought to your composer window in Gmail.

Panelizer project is a memory efficient desktop panel.
It works by holding all applets within the panel process itself.
Typical memory usage is currently around 1MB with 10 applets loaded.
Applets are provided by dynamically-loaded shared libraries, and new ones can be easily written using an easy C ABI.
Configuration is stored as XML and each applet has its own configuration data.
Here are some currently implemented applets of "Panelizer":
- launch menu (uses Open Desktop compatible entries)
- clock
- CPU instant load bar
- mail notifier (biff)
- removable drive mounter and ejecter
- network traffic monitor and (limited) launcher
- memory monitor
- audio mute