Free killer software for linux

Your computer has been invaded! Dozens of little viruses are pouring in via security holes in Microsoft Internet Explorer, Microsoft Outlook, Microsoft MSN Messenger and Microsoft Recycle Bin!!
Using your trusty mouse you must shoot the buggers before they can destroy your files! Some will steal them from their home directories and take them back to their security hole.
Others will just eat them right there on the spot! See how long you and your computer can survive the onslaught!
Main features:
- 3 different virus types.
- Builds directories and files to protect based on your computer!
- Increasing difficulty level
- Highscore table
- 3 difficulty settings

The Sheep Killer is a cross-platform 3d game where you control a Viking and must kill sheeps!
Each sheep gives you five points. While killing sheep you must watch out from rams! Theyll try to bite you, making you loose a life. You can also kill rams if you can, they give 10 points!
Enhancements:
- Adjusted choppy sounds on windows
- Adjusted a bug (dieing while changing the level)

ASK is a spam killer. This program (Active Spam Killer, or ASK for short) takes an "Active" approach in solving the problem: Everytime an email is received, a message is sent back to the sender asking for confirmation. If that sender does not confirm the message, it remains queued for delivery. If the sender confirms, the message is delivered and removed from the queue. The "confirmed" senders will be added to your "whitelist" and will never be sent another confirmation. Messages from these emails will always be delivered immediately . You can also specify an "ignorelist" for emails that should be always ignored and a "blacklist" that will cause a nastygram to be sent back to the sender everytime an email is received.

There are many traditional approaches to avoiding spam. The most common approach is based on "content-filtering": a program that attempts to classify incoming mails based on their content. This works partially, but in reality, its somewhat easy to find ways to avoid it.

ASK takes advantage of the fact that most spammers use invalid or fake "From:" address in their messages. When a new message arrives and the sender is unknown, ASK sends a "confirmation message" back, informing the sender that the original message has been queued, pending confirmation. When the sender confirms (a simple reply), ASK delivers the original message and adds the sender to a "whitelist". Further messages from this sender will be immediately delivered. It is also possible to ignore messages based on specific criteria, like senders email, subject and so on.

The goal of ASK is to block Spam mail before it is delivered to your mailbox. As we know, filtering alone is not effective since many times Spam mail contains no detectable elements.

ASK should be invoked from .forward (or .procmailrc if you are using procmail). The incoming message should be piped to ASK, which will be in charge of doing the actual delivery.

When ASK receives an email, if first checks the email address against your "ignorelist". If the address is listed there, its ignored completely. Then, the message is checked against your "blacklist". If its there, a nastygram is sent back to the sender with something like "Please stop sending me emails" in the Subject line.

The real fun happens when an email comes from an unknown user (i.e, someone not in any of your lists). In this case, ASK calculates the MD5 checksum of the message + a secret MD5 key (configured during installation time). This number is sent as part of a "confirmation message" back to the user. If the user replies to it, the confirmation number (in the subject) is recognized, the message is dequeued and delivered. If the user does not reply, the message remains queued until its removed.

The program has some intelligence to deal with specific cases. For instance, if a mail is sent to a non-existing user, the error message from mailer-daemon is ignored. This avoids seeing lots of "invalid user" messages in your inbox.

Another interesting "twist" is that messages coming from your own email address are never trusted. If the spammer knows your address he could easily fake your own address as the From: line. Messages coming from you will be identified by a "mailkey", a piece of string you always put on your message by default (maybe a piece of your own signature). Note that this has the added side-effect of allowing any messages coming in reply to a message you sent to someone (as long as that person keeps your "mailkey" in its quoted reply, a practice common these days).

The program never deletes any messages. For instance, if you send yourself a message without your mailkey (a possible Spam), it will be saved in a "Junk" mailfolder (you can specify this folder during the configuration).

Monkey Bubble is in a game in which you must explode all bubbles in the game area.
You explode bubbles by putting at least 3 of the same colour in contact. Any bubble that is connected to the top or the sides of the game area by bubbles you just exploded falls too.
Main features:
- svg graphics (try the fullscreen gameplay with Ctrl-F)
- gnome platform
- gstreamer to play music and sounds (still todo)
- C programming language, based on glib2.0, gtk2.0 and all those gnome stuff we all love (or should love
- released under GPL and waiting for contributors
Enhancements:
- The new monkey bubble (the gnome bustamove clone) version, 0.3.2, is out with a new killer feature: network game with 4 players.
- Of course the new release includes a bunch of bug fixes, leak fixes and even more eyecandy.

Ultratron is an arcade game where you have to destroy the four evil robots of the Apocalypse!
The last human has been slain by evil killer robots. You are the one remaining humanoid battle droid. Your mission is to avenge the human race, and destroy the four bots of the Apocalypse - Ieiunitas, Bellum, Lues and Letum!
Power up your droid with ever more powerful weaponry as you blast your way through the levels, avoiding Chasers, Turrets, Spawners, Minelayers, bombs, and bullets!
Main features:
- 70+ different robots to destroy
- 40+ levels of frantic shooter action
- 4 giant boss robots
- 10 powerups
- Bonus stages
- Online hiscore table

Koinkoin is a chat application for KDE.
History:
At the beginning was the Web. Then came Linux, and Slashdot came with it. This is when a small group of french OSS users/coders created Linuxfr, sort of a french Slashdot.
It had one killer-feature : a web-based chat (1). It is web-based but also has an xml file that is called backend file. A first application appeared that could display and automatically reload that backend. It allowed posting too.
Then other of these chats and other clients appeared. Those clients were called coincoins, referring to the sound made by a duck in french. I told you this was almost a french thing.
Koinkoin is a coincoin for KDE.
Enhancements:
- The configuration is stored into ~/.kde.
- The board and plugins are restored.
- The custom boards are fully managed in the dialog box.
- Original english labels updated.

PowerDNS project has developed a complete suite of technologies surrounding Internet Naming and email.
Internet Naming is at the core of all online activities and is involved in each and every transaction on the net. Email remains the killer application of the Internet.
Enhancements:
- This release contains two important security fixes, which should also solve the very rare reports of stability problems.
- Additionally, a new class of misconfigured domains will now always be resolved correctly, instead of intermittently.