https://vpncloud.ddswd.de/
https://github.com/dswd/vpncloud/

VpnCloud 是基于 UDP 的高性能点对点网状 VPN，支持强大的加密、NAT 穿越和简单的配置。 它以基于椭圆曲线密钥和 AES-256 的强大端到端加密的对等方式建立全网状自愈 VPN 网络。 VpnCloud 在主机上创建一个虚拟网络接口，并通过 UDP 将所有接收到的数据转发到目的地。 它可以在 TUN 设备（基于 IP）和 TAP 设备（基于以太网）上工作

Rust开发的

最大缺点是没有Android 客户
Tinc, Nebula, Wireguard 都有

Tinc uses UDP and TCP for connections. There is no option to only use the more efficient UDP.

Tinc requires users to create a key pair for each node and then exchange the public keys with all other nodes.

Nebula has a centralized take on security: It introduces a central authority that issues certificates for all nodes. The certificates also contain an allowed IP address, that will be enforced by other nodes. Nebula supports two symmetric ciphers (AES256 and ChaCha20) but the cipher has to be the same for the whole network.

Wireguard achieves its high throughput because it uses a kernel module to do the heavy lifting.