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We are very happy to announce that the source code of SoftEther VPN is released as open-source software under the GPLv2 license. The source code is provided as packages in .tar.gz and .zip formats, and is also published on our GitHub repository. You can build the full SoftEther VPN programs from the source code in Windows, Linux, Mac OS X, FreeBSD or Solaris computers. You can also generate your own customized installer packages of SoftEther VPN automatically from the source code.
SoftEther VPN is a product-class VPN software suite with popularity as a tool to build on-premise or cloud-base VPNs. SoftEther VPN Server has been installed into over 80,000+ server computers in Japan, United States, China, Taiwan, Iran, Germany, United Kingdom, France, Korea, India and other 164 regions (*1). SoftEther VPN supports Windows, Mac, Linux, and smartphones including iPhone and Android. SoftEther VPN supports multiple VPN protocols including SSL-VPN, OpenVPN, IPsec, L2TP, MS-SSTP, L2TPv3 and EtherIP, by a single instance of VPN server program. Individual and corporate network administrators can replace their legacy OpenVPN or Cisco's VPN router products by SoftEther VPN for integration.
One of the popular application of SoftEther VPN is VPN Gate (http://www.vpngate.net/). VPN Gate is "A Volunteer-Organized Public VPN Relay System with Blocking Resistance for Bypassing Government Censorship Firewalls" (*2). VPN Gate is a circumvention tool for bypassing governments' censorship firewalls. Many Internet users behind censorship firewall, including Chinese Great Firewall, are using VPN Gate to browse YouTube, Twitter and Facebook. Daily 110,000+ unique users (estimated by the number of client IP addresses) are using VPN Gate (*4). The offense and defense between VPN Gate and Chinese Great Firewall will be reported on USENIX NSDI 2014 International Conference (Seattle, April 2-4, 2014) (*3).
The text data of the source code of SoftEther VPN is approximately 380,000 lines. The total file size is 11 Mbytes. The source code includes not only the user-mode programs of SoftEther VPN, but also kernel-mode device driver codes for Virtual Network Adapter and Ethernet Bridging Module.
Many developers are now able to download the SoftEther VPN source code and study the technique how to design and implement a VPN protocol-engine to achieve the high-performance, multi-protocol support VPN communication with high-level penetrating-ability against firewalls. They can also study the know-how to implement kernel-mode device drivers which access to low-level Ethernet packet processing fabric on Windows and other modern operating systems.
Furthermore, because the source code is published under the traditional GPLv2 (GNU General Public License version 2), SoftEther VPN is granted to be modified, be recompiled, be embedded into derived software or hardware, or be redistributed with new branding, by any developers who have abilities to do so.
We believe that easy-to-use software-based VPN tools are necessary to achieve the free Internet world. Herein, the free Internet world means that any governments cannot censor or tap over the communication of people, and people can use communication technology without any kind of fears of suppression by governments. However, implementing such an easy-to-use VPN tool has required enormous difficult effort to implement the VPN engines. By using the source code of SoftEther VPN, any developer can exploit it to build his own VPN-based application. We hope that the release of SoftEther VPN source code will help such developers, and will also help to achieve the free Internet world in future.
*1
Current geographic locations of 81,424 SoftEther VPN Server users on January 4, 2014.
SoftEther VPN Server is installed on server computers around the world.
*2
The offense and defense between VPN Gate and Chinese Great Firewall will be reported on our academic paper: "VPN Gate: A Volunteer-Organized Public VPN Relay System with Blocking Resistance for Bypassing Government Censorship Firewalls" which was accepted on the USENIX NSDI 2014 International Conference (Seattle, April 2-4, 2014).
More details: https://www.usenix.org/conference/nsdi14/technical-sessions/presentation/nobori.
*3
The graph of number of daily unique IP addresses for VPN Gate clients.
*4
The ranking table of VPN Gate client source locations.
More details: http://www.vpngate.net/en/region.aspx
