= About HelenOS = HelenOS is a [wiki:HardwareSupport#Architectures portable] microkernel-based multiserver operating system designed and implemented from scratch. It decomposes key operating system functionality such as file systems, networking, device drivers and graphical user interface into a collection of fine-grained user space components. These components interact with each other via message passing. A failure of one does not directly harm others. HelenOS is therefore flexible, modular, extensible, fault tolerant and easy to understand. HelenOS trades compatibility with legacy operating systems and APIs for clean design. Most of HelenOS components have been made to order for HelenOS so its core is free of compatibility and glue layers, franken-components and the maintenance burden associated with them. HelenOS is open source / free software. Its source code is available under the [wiki:License BSD license]. Some third-party components and components based on [wiki:License GPL] software are licensed under [wiki:License GPL]. {{{ #!html Download HelenOS }}} {{{ #!html Contribute code }}}