NanoHttpd is a lightweight HTTP server designed for embedding in other applications. It's only one Java file, in two "flavors", one strictly Java 1.1 compatible, and one at "current" standards. It supports GET, POST, PUT, HEAD and DELETE requests, and supports file uploading with very small memory overhead. Temp file usage and the threading model are easily customized.
Ashd is an HTTP server that follows standard Unix philosophy for modularity. Instead of being a monolithic program with loadable modules, as most other HTTP servers seem to be, Ashd is simply a collection of much simpler programs, passing HTTP requests to each other using a simple protocol. The model also allows such handler programs to persist properly, so that, for example, session data can be kept in memory, connections to back-end services can be kept open, and so on.
GNU libmicrohttpd is a small C library for embedding HTTP server functionality into other applications. It is reentrant, fast, supports HTTP 1.1, and permits listening on multiple ports. The API is simple and still powerful enough to allow programmers to use the entire HTTP feature set. SSL/TLS support is available as an option.
mod-xslt is an Apache module which converts XML files into HTML files using XSLT stylesheets. It is able to parse dynamically-generated documents, both in POST and GET requests, includes a fully-featured language to choose the stylesheet to load from both configuration files and other .xml files, and provides extensions so stylesheets can access headers or get variables. It also supports redirects and dynamically-generated stylesheets.
Embedthis Appweb is a fast, little embedded Web server. It is unmatched in efficiency and serves pages at native speed, using an event-driven, non-blocking core to serve multiple requests using minimal resources. It has integrated caching and the Embedded Server Pages C-Language Web framework. Without compromising performance, it has extensive security controls and a rigorous security sandbox that helps protect the server and mitigate denial-of-service attacks. It is one of the most widely deployed embedded Web servers and is used in networking equipment, telephony, mobile devices, industrial control, and consumer and office equipment, and in high-performance Web services.
Tntnet is a Web application server for generating Web applications in C++. HTML pages with some additional tags for inclusion of C++ code are compiled into shared libraries and served from tntnet. It resembles PHP, JSP, or Mason, but the programming language used is C++, and the pages are compiled into native code before serving. Tntnet is fully multithreaded and supports HTTP keep-alive for best performance. Its dynamic pages are faster than static pages with other Web servers, while creating Web applications is simple.
phpSecurePages is a PHP module to secure pages with a login name and password. It can handle multiple user groups (each with their own viewing rights), store data in a MySQL database or a configuration file, and be used to identify your Web site viewers. It also has multiple language support and optional IP-based access restrictions.
Hiawatha is a secure and advanced Web server for Unix. It has been written with security as its main goal. It features advanced access control, prevention of SQL injection and cross-site scripting, banning of clients who try such exploits, the ability to run CGIs under any UID/GID you want, and many other features. These features make Hiawatha an interesting Web server for those who need more security than what the other available Web servers are offering. Hiawatha is also fast and easy to configure.
Alaya is a primitive chrooting Web server with basic WebDAV support. It can serve HTTPS and HTTP, and can authenticate using PAM, /etc/shadow, /etc/passwd, or using its own authentication files that allow for 'native' users that only have access to alaya content. It's intended to be a simple method of sharing content over WebDAV, and though it can be configured with a config file, it's easy to configure by command-line switches alone. Alaya always chroots to ensure that malicious users can't use '..' within a URL to access unintended documents, and that users can't accidentally leave documents in places outside of the chroot. It has a 'ChHome' mode that chroots users into their home directory and serves content from there. It supports .cgi scripts out of a trusted path (so not from within the chrooted WebDAV share) and read-only shared directories that are outside of the chroot (allowing access to shared content when in ChHome mode).