Free highly configurable software for linux

QOscC is a highly flexible and configurable software Oscilloscope with a large number of features. This includes support for any number of audio devices (ALSA, OSS, JACK and a number of Serial Multimeters), each with any number of channels that the hardware supports.
Each scope display can be configured individually to different display types and variants. e.g. you can chose from standard y-t mode (as on an usual oscilloscope), xy mode (e.g. for measuring the phase shift between two signals) of the FFT mode (to view a spectrum plot of the signal).
This software is intended for electronic hobyists, who cannot afford a hardware oscilloscope or need a simple spectrum analyzer as well as for musicans for doing basic signal analysis.
Main features:
- GUI in QT
- The number of Soundcards and Soundcard channels is not limited
- Supports spectrum display (FFT) with different scaling methods
- Input backends for OSS, ALSA and JACK
- Input level adjustment

TCVP is a video and music player and encoder/transcoder for Unix-like operating systems. It is primarily targeted at Linux, mainly because of lacking standards for audio and video output, and because the authors use Linux.
Adding support for other POSIX-compliant operating systems should be easy, provided that some means of displaying video and playing sound exists.
Main features:
- Pipelined design, allowing insertion of filters at any stage.
- Automatic selection of demuxers, decoders, and output drivers, based on user-defined order of preference.
- Buffering of decoded audio and video for smooth playback.
- Multi-threaded: multiple CPUs can be used if present.
- Multiple user interfaces. A flexible skin based X11 GUI is included, as well as a simple command line only interface.
- Playlist with shuffle and repeat.
- Highly configurable.
- No XML.

Elmo is a feature-rich, highly configurable and fast mail client. You could call it a Mail User Agent, but it offers much more than traditional MUAs.
Elmo should be easy and pleasant to use.
- The user should not be forced to configure many options before using it, nor read a long users manual. We provide a short script, elmoconf.pl (in the src/ directory) which will create a configuration file for you, providing reasonable defaults. You can start using the full power of Elmo in half a minute!
Elmo should be very fast and efficient.
- Elmo uses very efficient algorithms for several tasks. You shouldnt be surprised when you discover how fast it opens your mail folder with hundreds or even thousands of mail. For example, opening a folder with 7,000 mails lasts only four seconds!
You should be able to modify Elmo as you like.
- You, as a user of Elmo, are the most important in our project. You should be able to configure your mail client as you like, and nothing should constrain you. Thats why our configuration file has so many options: as your needs grow, you will be able to make Elmo behave exactly as you wish.
- Moreover, if you have suggestions, special wishes and advice, we would like to hear from you! If time allows, we will gladly incorporate your suggestions into a future version of Elmo.
Elmo will not require special external software.
- With traditional MUAs, such as Mutt, you usually have to set up an SMTP server, such as Sendmail, and often use additional tools like fetchmail to get your mail. With Elmo you can use this traditional approach but you dont have to: Elmo can send and receive mail on its own, which means you are less dependent.
Elmo should have a good, modular design.
- While it may not seem important to you, it does influence our ability to add new features to Elmo. We worked hard to make Elmo easily extensible, using best software-development methodologies.
Main features:
- SMTP support (with authentication support)
- POP3 support
- a Bayesian mail filter!
- an address-book
- colors
- threads
- keymaps and hooks
- maildir and (partial) mbox support
- MIME support (including support for encoded headers)
- partial GPG support (decoding, and signature verification)
- OpenSSL support
- partial UTF-8 support
- interactive search

KBiff is a "biff" or new mail notification utility. It is highly configurable but very easy to use and setup. It tries to combine the best of the features of most of the "other" biff programs out there.
KBiff supports all major mailbox formats: mbox (Berkely style), maildir, mh, POP3, IMAP4, and NNTP. As of 3.7, it also supports POP3 and IMAP4 with SSL. As of 3.8, it supports CRAM-MD5 and APOP authentication.
KBiff is also part of the KDE project. Among other things, this means that it has support for session managment (it "remembers" the last state it was in before you logged off) and can be docked into the panel.
Main features:
- Pure GUI configuration. No more command line parameters to remember (well, one optional one to make things easier for some people) or strange config files. All settings for KBiff can be done from one setup dialog.
- Session Management. KBiff starts up with the same configuration you left it with.
- Panel Docking. KBiff can be docked into the panel very easily. Handy when you are monitoring several mailboxes and dont have room anywhere else.
- Animated GIFs. You can use animated GIFs as your icons.
- Sounds. KBiff has an option to play .wav files when new mail arrives.
- POP3, IMAP4, NNTP, Maildir, MBOX, MH. KBiff supports all major mailbox formats!
- Multiple Mailbox. KBiff can monitor several mailboxes with one instance.
- Others. KBiff has scads of other options.
Enhancements:
- pdated automake admin dir to compile with latest SuSE
- Updated documentation slightly

JVOIPLIB is an object-oriented Voice over IP (VoIP) library written in C++.
It is based upon work done for my thesis at the School for Knowledge Technology (or School voor Kennistechnologie in Dutch), a cooperation between the Hasselt University and the Maastricht University.
A part of this library was developed at the Expertise Centre for Digital Media (EDM) in Diepenbeek, Belgium. The EDM is a research institute of the Hasselt University.
Main features:
- Easy VoIP session creation and destruction.
- Highly configurable sessions: sampling rate, sample interval, compression type, ... can all be selected by the user. These features can also be changed during a session.
- Openness and extensibility: the object-oriented nature of the library makes it very easy to add features; new components can easily be tested by registering them as User Defined modules.
- Support for 3D effects: for my thesis I also did some research and development about VoIP in networked virtual environments, which included adding 3D effects to sound. For this reason, Ive added this feature to the library.

Configurable Audible User Interface in short caui is a simple plugin-based audible user interface.
Plugins use speech synthesis software to interact with a user and perform specific actions. The main method of input is a keyboard or number pad.
This project is the successor to the Blind MP3 Player.
Enhancements:
- caui-cmd will exit immediately if caui has an mplayer process forked.

JRelaxTimer is a timer (or alarm clock) that allows Web-users to open specific Web-pages at selected time intervals. JRelaxTimer, for example, could be installed on the company Intranet and used by employees to execute specific tasks at selected time intervals.
Built as a browser-independent and highly-configurable Java Applet, JRelaxTimer could be easily customized with your own graphics and time format to achieve an unlimited variety of appearances and behaviors. JRelaxTimer includes by default 232 images (13 different sets of digits).
JRelaxTimer is composed by some independent components that could be showed or hidden by option (logo, buttons, displays, selectors)
Main features:
- browser-independent, works fine with any browser that support at least Java 1.1
- support two different page selection methods
- customizable background colors
- customizable background images
- customizable graphic images for digits and symbols
- 232 ready to use images (13 sets of digits)
- support for image transparencies
Enhancements:
- The license was changed to the GPL.