Free can be defined software for linux

Cancerbero (the watchdog of the ports) is a portscan engine based in nmap. It will scan the hosts of a defined net once in every configured interval and it will store the results in a mysql database. It comes with a Web interface to access the scan info.
Main features:
- Graphical configuration.
- Multiple sensors scanning can be deployed.
- There is no limit in the number of ranges to scan.
- Discover the alive (not firewalled) hosts.
- Scans 1-65535 TCP ports of each host.
- Attempts to discover the REAL application and version behind each port.
- Attempts to discover the OS of each host.
- Store all the information in a MySQL database.
- Rescan each host at a defined interval.
- White-Lists with hosts or ranges that you dont like to scan can be defined.
- The information can be access through a graphical interface? (web based)
- You decide how many scans should be archived.
- Stats of all the data are provided.
Install instructions can be found in: http://cancerbero.sourceforge.net/wikka.php?wakka=Install

Guifications is a Gaim plugin that displays msn style "toaster" popups in a user defined corner of the screen.

Guifications is highly configurable, and easy to use. There are a ton of preferences, that may be daunting at first, but are pretty straight forward.

Rainlendar project is a customizable desktop calendar.
Rainlendar is a feature rich calendar application that is easy to use and doesnt take much space on your desktop. The application is platform independent so you can run it both on Windows and on Linux. The appearance can be customized with skins and you can even mix different skins together.
It is possible to use Rainlendar with other calendar applications too. Rainlendar uses the standard iCalendar format to store its events and tasks so you can easily transfer them between applications. You can also subscribe to online calendars and see your Outlook appointments directly in Rainlendar*.
Rainlendar is an unicode application and support localization so you can use it on your own language.
All the coming events are shown in a separate list where you can see the weeks events at one glance. You can decide how many days in advance you want to see in the list. Different events can have a different appearance in the list so you can easily spot the important events from the others. The icons in the calendar are also available in the event list and other windows to make it easier to separate the events.
You can also have a separate list for your long term tasks. The task list can be arranged several ways so that you can keep it better organized. You can also set a due date for the tasks to make sure youll remember to do them on time.
Youll also get an alarm when an event or task is due so that you dont miss it. The alarm can be defined to be set off any duration before the actual event so you have time to prepare for it.
And thats not all. Check the list of features for better overview of all the things Rainlendar can do. If you find it useful go to the download page and get yourself a copy.
*Network shared calendars and Outlook support are available only in the Pro version
Main features:
- Small and lightweight
- Different type events can have different appearence
- Supports Windows transparency
- Synchronizes events between several clients
- Localized for multiple languages
- Shows an alarm when an event is due
- Shows Outlooks appointments
- Includes a todo-list
- Works also as Litestep plugin
- Displays the current date in tray icon
- Can stick to the desktop (i.e. doesnt hide with Show Desktop)
- Hotkeys for quick access
- Easy skinning with an UI
- Can be controlled from 3rd party applications with !bangs

QAA is a XUL Mozilla Firefox extension that performs a user supplied test list on a Web application. Test sessions can be defined by example.
A report is generated when sessions are replayed.
Enhancements:
- This release can load and save .qaa files (Quality Assurance Agent file format), record a journey in the tested site using definition by example, and perform a test bench with a log style report.

Some would call TreeLine an Outliner, others would call it a PIM. TreeLine just stores almost any kind of information.
A tree structure makes it easy to keep things organized. And each node in the tree can contain several fields, forming a mini-database.
The output format for each node can be defined, and the output can be shown on the screen, printed, or exported to html.
Main features:
- Stores almost any type of information, including plain text, HTML, numbers, dates, times, booleans, URLs, etc.
- The tree structure helps keep things organized.
- Each node can have several fields that form a mini-database.
- Several node types, with different sets of fields, can be included in one file.
- The node format, including fields, output lines and tree-view icon, can be defined for each node type.
- The right-hand view can show one of three views - for showing output, editing node data and editing node titles.
- Clicking on URL fields in the output view opens the link in an external web browser.
- There are internal link fields that select another node based on a reference or a keyword.
- An executable link can run an external program or open a file when clicked.
- Formatting information can be copied from another TreeLine file.
- There are two search commands available.
- Undo and redo commands are available for all modifying operations.
- The formatted output can be printed with parent/child lines and headers and footers.
- TreeLine files are XML by default, but there are options for automatically compressing or encrypting the files.
- The data can be exported to HTML.
- An XSLT file can be exported to work with the XML TreeLine files.
- Tab-delimited tables and tab-indented text files can be imported and exported. Plain text files and Treepad files can be imported.
- Mozilla and XBEL format bookmark files can be imported and exported.
- Generic XML files can be imported and exported, allowing TreeLine to function as a crude XML editor.
- Batch file conversions can be done from a command line interface.
- There are several sorting options.
- The nodes can be filtered.
- Text data can be spell checked (requires an external program - see the System Requirements section).
- Data can be automatically arranged using either parent references or categories from data fields.
- There is an outline numbering feature.
- There are many other options for customization, including user-defined keyboard shortcuts.
- The user interface and documentation are available in English, French and German.

Essential Management provides a project management system for organizing and writing technical documents.

Essential Management is a multi-user project management system for managing intricate and complex information. Its initial purpose was to allow software development teams to create, maintain, track, and store project requirements on a multi-project basis in a multi-user environment. It has now become more abstract in the type of data it can maintain, allowing the easy addition of new data models and other expansions. Information can be stored in any of several database management systems, and can take advantage of a networked DBMS.

The first and most important feature of the application is that data is stored in a central data repository managed by some database management server; initially PostgreSQL fills this role, but support for others are growing. The repository is fully searchable. An alternative data storage format exists in the form of a locally maintained XML file if the user wishes to use it.

One of the key features Essential Management was designed around is the ability to define and maintain relationships between requirements. Using the software requirement model as an example, our application allows users to define projects; each project is composed of zero or more root requirements, which are typically business level requirements. Each business requirement has zero or more sub-requirements, which either refine the parent business requirement or dive into the functional requirements which allow the business requirement to be achieved. This tree continues to branch and grow deeper until the most basic level that the user wishes to define is reached.

In addition the relationship between parent and child requirements, relationships can be defined between requirements not in the same branch. These relationships may have any meaning the user wishes to define and can be unidirectional or bi-directional.

Essential Management implements the concept of user level permissions, which provides a small measure of security for the projects and their requirements. Additionally, creation of and changes to requirements can be traced to the user who initiated the action.

Finally, the application provides a means to track changes made to requirements during their lifetime so it is possible to determine when a change was made, what information was changed and who edited the requirement.