Internet/Web Servers
freeware
Tftpd32
Tftpd32 includes DHCP, TFTP, SNTP and Syslog servers as well as a TFTP client. The TFTP client and server are compatible with TFTP option support (tsize, blocksize and timeout), which allows for faster data transfers. Some extended features such as directory facility, security tuning, interface filtering; progress bars and early acknowledgments enhance usefulness and throughput of the TFTP protocol for both client and server. And the included DHCP server provides automatic or static IP address assignment.
open source
ioFTPD
ioFTPD is a professional high performance Ftp Server for Windows. It has a wide range of flexibility through its tcl scripting extension. Features vfs, low resource, detailed user access limitation, siteop, open source, and huge range of user made scripts.
freeware
Apache HTTP Server
Apache has been the most popular web server on the Internet since 1996. The Apache project is an effort to develop and maintain an open-source HTTP server for various modern desktop and server operating systems, such as UNIX and Windows NT. The goal of this project is to provide a secure, efficient and extensible server which provides HTTP services in sync with the current HTTP standards.
freeware
XAMPP
XAMPP is an easy-to-install Apache distribution containing MySQL, PHP and Perl. It is really very easy to install and to use: just download, extract and start.
open source
PostgreSQL
PostgreSQL is a powerful, open source relational database system. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness. It runs on all major operating systems, and is highly scalable both in the sheer quantity of data it can manage and in the number of concurrent users it can accommodate. There are active PostgreSQL systems in production environments that manage in excess of 4 terabytes of data.
open source
FileZilla Server
FileZilla Server is a small and fast FTP Server. The server looks like the famous G6, but it is free.