RouterOS is a stand-alone operating system based on Linux kernel. It powers MikroTik hardware devices, but is also available for virtual machines.
The following list shows features found in the latest RouterOS release:

Hardware Support

• i386 compatible architecture
• SMP – multi-core and multi-CPU compatible
• Minimum 32MB of RAM (maximum supported 2GB, except on Cloud Core devices and CHR installations, where there is no maximum)
• IDE, SATA, USB and flash storage medium with minimum of 64MB space
• Network cards supported by linux v3.3.5 kernel (PCI, PCI-X)
• Partial hardware compatibility list (user maintained)
• Switch chip configuration support

Installation

• Manual:Netinstall: Full network based installation from PXE or EtherBoot enabled network card
• Manual:CHR: RouterOS version intended for running as a virtual machine
• Netinstall: Installation to a secondary drive mounted in Windows
• CD based installation

Configuration

• MAC based access for initial configuration
• WinBox – standalone Windows GUI configuration tool
• M:Webfig - advanced web based configuration interface
• MikroTik - Android and iOS based configuration tool
• Powerful command-line configuration interface with integrated scripting capabilities, accessible via local terminal, serial console, telnet and ssh
• API - the way to create your own configuration and monitoring applications

Backup/Restore

• Binary configuration backup saving and loading
• Configuration export and import in human readable text format

Firewall

• Statefull filtering
• Source and destination NAT
• NAT helpers (h323, pptp, quake3, sip, ftp, irc, tftp)
• Internal connection, routing and packet marks
• Filtering by IP address and address range, port and port range, IP protocol, DSCP and many more
• Address lists
• Custom Layer7 matcher
• IPv6 support
• PCC - per connection classifier, used in load balancing configurations
• RAW filtering to bypass connection tracking.

Routing

• Static routing
• Virtual Routing and Forwarding (VRF)
• Policy based routing
• Interface routing
• ECMP routing
• IPv4 dynamic routing protocols: RIP v1/v2, OSPFv2, BGP v4
• IPv6 dynamic routing protocols: RIPng, OSPFv3, BGP
• Bidirectional Forwarding Detection ( BFD)

MPLS

• Static Label bindings for IPv4
• Label Distribution protocol for IPv4
• RSVP Traffic Engineering tunnels
• VPLS MP-BGP based autodiscovery and signaling
• MP-BGP based MPLS IP VPN
• complete list of MPLS features

VPN

• IPSec – tunnel and transport mode, certificate or PSK, AH and ESP security protocols. Hardware encryption support on RouterBOARD 1000.
• IKEv2 support
• AES-NI hardware acceleration support for IPSec
• Point to point tunneling ( OpenVPN, PPTP, PPPoE, L2TP, SSTP)
• Advanced PPP features (MLPPP, BCP)
• Simple tunnels ( IPIP, EoIP) IPv4 andIPv6 support
• 6to4 tunnel support (IPv6 over IPv4 network)
• VLAN – IEEE802.1q Virtual LAN support, Q-in-Q support
• MPLS based VPNs

Wireless

• IEEE802.11a/b/g wireless client and access point
• Full IEEE802.11n support
• Nstreme and Nstreme2 proprietary protocols
• NV2 protocol
• Wireless Distribution System (WDS)
• Virtual AP
• WEP, WPA, WPA2
• Access control list
• Wireless client roaming
• WMM
• HWMP+ Wireless MESH protocol
• MME wireless routing protocol

DHCP

• Per interface DHCP server
• DHCP client and relay
• Static and dynamic DHCP leases
• RADIUS support
• Custom DHCP options
• DHCPv6 Prefix Delegation (DHCPv6-PD)
• DHCPv6 Client

Hotspot

• Plug-n-Play access to the Network
• Authentication of local Network Clients
• Users Accounting
• RADIUS support for Authentication and Accounting

QoS

• Hierarchical Token Bucket ( HTB) QoS system with CIR, MIR, burst and priority support
• Simple and fast solution for basic QoS implementation - Simple queues
• Dynamic client rate equalization ( PCQ)

Proxy

• HTTP caching proxy server
• Transparent HTTP proxy
• SOCKS protocol support
• DNS static entries
• Support for caching on a separate drive
• Parent proxy support
• Access control list
• Caching list

Tools

• Ping, traceroute
• Bandwidth test, ping flood
• Packet sniffer, torch
• Telnet, ssh
• E-mail and SMS send tools
• Automated script execution tools
• CALEA
• File Fetch tool
• Advanced traffic generator

Other features

• Samba support
• OpenFlow support
• Bridging – spanning tree protocol (STP, RSTP), bridge firewall and MAC natting.
• Dynamic DNS update tool
• NTP client/server and synchronization with GPS system
• VRRP v2 and v3 support
• SNMP
• M3P - MikroTik Packet packer protocol for wireless links and ethernet
• MNDP - MikroTik neighbor discovery protocol, supports CDP (Cisco discovery protocol)
• RADIUS authentication and accounting
• TFTP server
• Synchronous interface support (Farsync cards only) (Removed in v5.x)
• Asynchronous – serial PPP dial-in/dial-out, dial on demand
• ISDN – dial-in/dial-out, 128K bundle support, Cisco HDLC, x75i, x75ui, x75bui line protocols, dial on demand