What are some alternatives?
When comparing DD-WRT and MikroTik RouterOS, you can also consider the following products
OpenWrt - OpenWrt is an open-source firmware based on Linux for wireless routers
pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more
Gargoyle - Gargoyle Router Firmware home page
ClearOS - A very good alternative for Windows Server, for free
LibreMesh - An Open Source Sofware for Geek-free Mesh Community Networks.
IPFire - IPFire is a server distribution with intended to use as a firewall.