Open Source C Firewall Software for Windows

Privoxy is a non-caching web proxy with advanced filtering capabilities for enhancing privacy, modifying web page data and HTTP headers, controlling access, and removing ads and other obnoxious Internet junk. Privoxy has a flexible configuration and can be customized to suit individual needs and tastes. It has application for both stand-alone systems and multi-user networks.

Advanced Onion Router is a portable client for the OR network and is intended to be an improved alternative for Tor+Vidalia+Privoxy bundle for Windows users. Some of the improvements include UNICODE paths, support for HTTP and HTTPS proxy protocols on the same Socks4/Socks5 port with HTTP header filtering that generates fake identity-dependent headers every time the identity is changed (proxy chains are also supported), support for NTLM proxies, a User Interface that makes Tor's options and actions more accessible, local banlist for forbidden addresses, private identity isolation, a point-and-click process interceptor that can redirect connections from programs that don't support proxies, also giving them fake information about the local system and support for .onion addresses. Also, it can estimate AS paths for all circuits and prevent AS path intersections, it can restrict circuits to be built using only nodes from different countries, can change circuit lengths and more.

Endian Firewall Community (EFW) is a "turn-key" linux security distribution that makes your system a full featured security appliance with Unified Threat Management (UTM) functionalities. The software has been designed for the best usability: very easy to install, use and manage and still greatly flexible. The feature suite includes stateful packet inspection firewall, application-level proxies for various protocols (HTTP, FTP, POP3, SMTP) with antivirus support, virus and spam-filtering for email traffic (POP and SMTP), content filtering of Web traffic and a "hassle free" VPN solution (based on both OpenVPN and IPsec).

PeerGuardian is a privacy oriented firewall application. It blocks connections to and from hosts specified in huge blocklists (thousands or millions of IP ranges). Its origin seeds in targeting aggressive IPs while you use P2P. PeerGuardian Linux: Not developed actively anymore. Team might still be around. Some unreleased changes on git. Outdated technology. Peerguardian OS X: Not developed anymore. We've lost contact with the OS X developer. PeerGuardian Windows: Not developed anymore. It's highly recommended to use PeerBlock instead, which is a continuation of PeerGuardian's development in Windows, with bug fixes and support for Windows Vista and Windows 7. Collaboration with peerblock.com is welcome! PeerGuardian is an open project. Not only is its source code open for you to read, use, and modify - but the project is open for you to join and contribute in any form (code, documentation, bug reports, web and support).

wipfw - IPv4 packet filter and traffic shaper for Windows based on IPFW (FreeBSD firewall).

The Nemesis Project is designed to be a command line based, portable human IP stack for UNIX-like and Windows systems. The suite is broken down by protocol, and should allow for useful scripting of injected packets from simple shell scripts.

Collection of open source security tools that enhance the ability of people and companies to secure their environment. These tools will build upon the foundation laid by the security community.

ModSecurity is a web application firewall that can work either embedded or as a reverse proxy. It provides protection from a range of attacks against web applications and allows for HTTP traffic monitoring, logging and real-time analysis.

Netdeep Secure is a Linux distribution with focus on network security. Is a Next Generation Open Source Firewall, which provides virtually all perimeter security features that your company may need. It offers Web content filters, ensuring better performance of the network, allowing users to use the service efficiently and securely, providing a deep control of the use of the Web access service, blocking access to unwanted websites, Virus, Spam, Applications and intrusion attempts. Its configuration is made entirely by the web interface.

Blocks "known bad" IP-addresses from accessing your machine, especially corporate/governmental agencies. This is a fork of PeerGuardian 2, fixing various Vista/Win7 problems.

[antispam] MailCleaner is an anti-spam / anti-virus filter SMTP gateway with user and admin web interfaces, quarantine, multi-domains, multi-templates, multi-languages. Using Bayes, RBLs, Spamassassin, MailScanner, ClamAV. Based on Debian. Enterprise ready. MailCleaner is an anti spam gateway installed between your mail infrastructure and the Internet. It includes a complete GNU/Linux OS and a graphical web interface for user and administrative access. It comes in the form of virtual machine templates.. - fully compatible with any SMTP mail server (Exchange, Zimbra, O365,...) You can install now MailCleaner within the following virtual environments: qcow2 (KVM, Proxmox, OpenStack, Xen) ova (OVA, VMware ESXi, VMware Workstation, Fusion) vhd (Asure, VirtualPC) vhdx (Hyper-V) AMI (Amazon) Dedicate a server to MailCleaner, and you will have a working professional mail filter in less than an hour.

Flexible web-based firewall log analyzer, supporting netfilter and ipfilter, ipfw, ipchains, cisco routers and Windows XP system logs, and mysql or postgresql database logs using the iptables ULOG or NFLOG target of netfilter others mapped to the ulogd format with a view. Fully supports IPv6 for database logs, and netfilter and ipfilter system file logs. Also supports Maxmind's GeoIP version 2 location databases. For Linux, FreeBSD, OpenBSD, Solaris, OSX,etc.

Knocker is a simple, versatile, and easy-to-use TCP security port scanner written in C, using threads. It is able to analyze hosts and the network services which are running on them. It is available for Linux, FreeBSD, Unix, and Windows95/98/2000.

Simple TDI-Based Open Source Personal Firewall for Windows NT4/2000/XP/2003

m0n0wall is a powerfull Router Application Platform.

Bootable CD Forensics/Virus Scanning/Recovery/PenTesting platform

AMaViS is a script that interfaces a mail transport agent (MTA) with virus scanners.

VTD-XML is the next generation XML parser/indexer/editor/slicer/assembler/xpath-engine that goes beyond DOM, SAX and PULL in performance, memory usage, and ease of use.

The program implements the CIDR merging with whitelisting (network exclusion). Output will be summarized to be as small as possible. The program has been widely used for blacklist merge and optimization.

The doorman guards the door of a server, manipulating firewall rules to admit only recognized parties. Allows Silent Running - a server with all ports CLOSED. Linux-BSD-OSX server & client; C source & docs + Windows client binary. GPL.

Geo Firewall performs blocking of network traffic based on geography (geo IP), allows to add custom subnets, allows exceptions on ports for incoming traffic for specific geography, keeps visual and persistent logs, shows statistics, automatically updates geographical database.

Implements a Windows NT VPN peer to Olaf Titz's CIPE VPN for Linux NOTE: The distribution must be downloaded from the home page

LanBiz is a free, Open Source Server Suite, mostly fitted for SOHO (Small Office/Home Office) environments. The final LanBiz will include: an internet gateway/firewall, proxy, mail, file/print, fax/telephony server and more!

Linux Authentication Gateway which allows to make dynamic firewall rules based on usernames.

CartoReso intends to facilitate enterprise computer network mapping.