Free operating income software for linux

J Operating System is primarily intended for programmers.
Target Users:
- Hobbiests--You used to buy computers to do programming. They didnt do much else. Windows doesnt even come with a compiler, which is ironic since Bill Gates wrote BASIC. The "J" operating system is primarily intended for programmers. Ive attempted to lower the bar, so amateurs can contribute. I hope to recreate the dynamic environment that used to exist when the Commodore 64 was around and everyone was creating odd-ball software.
- Researchers--Im sure many lab researchers still use DOS because they have to interact with hardware, which is difficult with Windows.
Main features:
- No security! You can access all ports, memory and disk blocks to your hearts content. When youre working with your own computer, security just gets in the way and makes things slow--I hate anti-virus and anti-spyware because they just slow things down. When you know you dont have a risk, have no secrets and do regular back-ups, who needs security?
- Uniformity
- There is no virtual memory and everyone is on the same address-map. You can easily communicate between tasks, passing addresses. Addresses start at a base of zero and, essentually, segment registers are not used.
- There is basically one language to learn called "C+" which is a little more than "C", but less than "C++". You dont need to learn a scripting langauge because everything uses this syntax.
- There is an extension of ASCII called "J" rich text which allows colors, links, graphics and various widgets in your documents. This format is used in source code, documents, help, menus, etc.
- Support for compressed, encrypted and contiguous files.
- FAT32, FAT12 and ISO9660 filesystems.
- Blazing-fast compiler which can recompile everything in 5 seconds. It doesnt optimize.
- All source code is included and its still around a Meg.
Hardware:
- PS/2 mouse and keyboard
- VGA graphics
- Some hard drives. Must be on the primary or secondary IDE controller and support LBA28. Drives of 120Gig are the limit.
- Some CD-ROM/DVD drives, including burning.
- Some floppies. Just 1.44Meg and not all types.
- No USB support yet
- No network support yet
- ASCII printers on the parallel port are supported.

The Contiki Operating System is mostly known as an operating system for networked embedded systems. A few years ago, however, Contikis primary claim to fame was its Commodore 64 port.
With the help of JAC64, a Java-based C64 emulator developed by my colleague and fellow Contiki developer Joakim Eriksson, you can now experience the C64 port of Contiki 1.2-devel1 again, directly in your web browser!
Enhancements:
- Contiki now does dynamic run-time loading and linking of standard ELF files.
- Rime, a protocol stack designed for low-power radio communication, has been added.
- Cooja, a Java-based network simulator for Contiki is included.
- The build system has been reworked to allow for easy cross-compiling for many platforms.
- A new port for the Tmote Sky sensor board has been added.

DEX Extensible Operating System is an operating system specifically designed for educational and research use. DEX Extensible Operating System allows for the dynamic reconfiguration and customization of various system services using concepts found in extensible operating systems.
It aims to create an operating system design thats easy to understand while having features that are common in todays modern operating systems. Unlike other small operating systems, it is powerful enough to support simple applications that require multithreading and file management.
Its architectural design, with the help of Aspect-Oriented programming, enables easy modification and extensibility. It was developed in C and runs on PCs with 80386 processors or higher.
Enhancements:
- This version is released with a floppy image and the kernel source code.
- The release contains peformance enhancements, source code clean-ups, and a makefile for use with GNU make.