Base Applications
The Photon Server SDK includes several applications that should provide a good starting point for your own development. Below is described what each does and for which game-style it's a useful basis.
Lite
The Lite Application is probably referenced most often. It implements the basic framework for room based games in which players get together to play a match in a small group. Each room reflects a game and is identified by its name. Anyone connected can join and leave without restriction. Inside a room, any client can raise events to send data across to the others. Properties can be set for rooms and actors to keep certain values available for everyone joining.
Games which don't need an authoritative server can be built on top of Lite without modifications.
This application can easily be extended with server-side logic per room. Matchmaking could group players in rooms, depending on your game's requirements.
Read more: Lite and Lite Lobby
Lite Lobby
The Lite Lobby is an example of how to build on top of Lite and extend it's functionality. Lite Lobby adds new types of rooms: Lobbies. These won't send join/leave event but list currently used room names. The player (or client code) can easily chose from running games. Additionally, the count of users in a room is provided.
This application adds "manual matchmaking" to Lite and could also be a basis for your game.
Read more: Lite and Lite Lobby
MMO
The MMO Demo Application is a good solution for games where all players share a large world. It provides interest management and most common base classes for items, actors, properties and more.
Typically games with a shared world contain more game-specific logic on the server side, so this application should be understand as a framework.
Policy
The Policy Application runs on Photon to send the crossdomain.xml. Webplayer platforms like Unity Webplayer, Flash and Silverlight request authorization before they contact a server.
It has it's own page in the DevNet: Policy Application
CounterPublisher
This application reads and forwards local PerfMon Counters of Photon Core to the Dashboard. It does not interfere with other applications and client should not connect to it.