ClearOS is an open source, Linux-based operating system for small to medium enterprises. It is a web-based server platform that provides an array of features, such as networking, server, storage, email, messaging, and a suite of business applications. It is designed to be easy to install, configure and manage. ClearOS is designed to provide a secure, reliable and cost effective platform to build and maintain a business network. It offers a wide range of advanced features and services that are needed to build and manage a secure, reliable and cost effective IT infrastructure. ClearOS also provides a comprehensive web-based user interface that allows administrators to manage the system, create virtual machines, configure networking, manage users, and more. It also offers a wide range of tools and applications that help users develop and deploy web applications.
DD-WRT is only a router distribution, designed for small routers, ClearOS is a fully functional distribution for servers with much broader functionality.