List of Full-Mesh VPN Solutions

Introduction

Many are interested in Full-Mesh (or P2P) VPNs; they want to use them for games with friends, for connecting remote offices, servers, and for anything else. Regular VPNs, such as OpenVPN or PPTP, pass all traffic through the central server, and Full-Mesh connect directly to the nodes, often breaking through NAT.

With your servers (mainly for games):

Tunngle
Basic and Premium. Windows only.

VPN for games, analog of Hamachi. Zero-config through the program server. Chat with the ability to transfer files, voice chat based on Ventrillo and Mumble. There is a mini firewall.
In the free version, you can create a room for up to 32 people, which is deleted
after 3 days of inactivity. You cannot configure a mini-firewall, it blocks ports
1-1024 and all protocols except tcp, udp and icmp. Punches NAT.
Premium makes it possible to create rooms for up to 255 people, hide rooms from the
catalog, change the nickname, use QoS, configure the mini-firewall,
use the nickname instead of ip (dns).

Social VPN
Open Source. Windows and Linux. C #

Zero-config with XMPP as a backend, integration with Gtalk. It breaks through NAT, connects directly, or uses its own servers if this is not possible. There is a DNS.

Remobo
Free. Windows, Linux, and MacOS.

An analogue of Hamachi, zero-config via the program server. There is a built-in chat. It is possible to use other computers as a proxy. Punches NAT.
There is a PRO version, which is distinguished by the presence of a daemon with CLI.

Without your servers:

NeoRouter
Free. Windows, Linux, MacOS, FreeBSD, Android.

There is a portable version and a web client. IPv6 support, breaks through NAT.

GBridge
Free. Windows only.

Zero-config via Gtalk and Gmail. VPN, VNC, Sharing, synchronization and backup files.
Image preview generation, cataloging, streaming audio and video (using web-interface).
It breaks through NAT, the node server is missing.

P2PVPN
Open Source. Windows and Linux. Java

VPN and chat between peers. Used by BitTorrent (specifically the OpenBitTorrent tracker) to search for peers on your network. NAT does not break through, requires at least one member of the network to have an open port, no server node.
The project stalled a bit, the latest version was released in 2010.

Wippien
Open Source. Windows and Linux.

Uses XMPP as a backend, integration with Gtalk. Punches NAT.

For server use:

tinc
open source. Windows, Linux, * BSD, MacOS, Solaris, iPhone.

Old project, easy configuration, no server nodes. IPv6 support, breaks through NAT.

PeerVPN
Open Source, Linux, and FreeBSD. Unofficial ports for MacOS and Windows.

IPv6 support, breaks through NAT.