SoftEther VPN is currently freeware, and is planned to be published as open-source software (GNU General Public License) in the middle of 2013.
Two reasons why the source code hasn't been released yet.
Reason 1: Laziness Translator
First, we are now preparing the source code translating Japanese a huge number of inline comments into English before publishing. In the development phase we wrote all source-code with Japanese comments. We decided to release the source code later, so one of our member (a English speaker) began to perform translation. However, he is so lazy. So translation task will take more time.
Reason 2: Copyright Problem
In fact our work has several related people and institutions. We have to take the agreement to disclosure the entire source-code. Otherwise copyright legal issue will occur. If one of our related copyright-holder will deny the disclousing his source-code, we have to exclude the affected parts.
We are trying to resolve the above two reason as soon as possible, and aiming to release the source code of SoftEther VPN in middle of 2013 or earlier.
UT-VPN (former version) Source Code is Available
SoftEther Project is the successor of UT-VPN Project (University of Tsukuba VPN Project). UT-VPN Project was initiated in 2010, by Daiyuu Nobori at University of Tsukuba. UT-VPN is Japanese Only software.
You can download UT-VPN binary and source-code. Please note that UT-VPN includes no L2TP/IPsec, OpenVPN nor MS-SSTP VPN protocol modules. In the source-codes there are a lot of Japanese comments. It it pretty difficult to read it if you don't speak Japanese.
