M README.md → README.md

@@ -39,6 +39,15 @@ * `/random`: Read-only, get a random number from 0 to 99.
 
 * `/grandom`: Read-only, get a random number from 0 to 99 -- These are doled out on a per-realm basis, and the number stays the same until everyone in the realm has had a chance to read it. If you've already read it this round or aren't in a realm, it will be empty.
 
+### realm format
+
+Each realm directory on the server should have the following files:
+
+  * `realm`: Basic data for the realm, file should contain only the maximum number of members, the master's name, and the password hash, if any (otherwise 0), separated by spaces.
+  * `universe`: The actual game state for the realm as key value pairs, one per line, like `KEY = VALUE`; limit 15 characters for keys, 63 for values.
+  
+The realm should be synchronized to disc when realm membership, limit, or password change. Fenagling some periodic autosave should be possible...
+
 ## configuration
 
 `config.h` in the source contains the following configuration macros:
@@ -46,11 +55,24 @@
   * `MAX_USERS`: the maximum number of simultaneous users able to attach to the `xrxs` service
   * `DATA_DIR`: the path to the root of the cartridge and realm storage; can be absolute or relative to the `xrxs` executable, but must have the trailing `/`
 
-## realm format
+## build/run
 
-Each realm directory on the server should have the following files:
+`xrxs` is built/tested in a Linux environment with `plan9port` and the C standard library as the only dependencies. With minimal modifications it will probably run just as well on *BSD, WSL, and MacOS.
 
-  * `realm`: Basic data for the realm, file should contain only the maximum number of members, the master's name, and the password hash, if any (otherwise 0), separated by spaces.
-  * `universe`: The actual game state for the realm as key value pairs, one per line, like `KEY = VALUE`; limit 15 characters for keys, 63 for values.
-  
-The realm should be synchronized to disc when realm membership, limit, or password change. Fenagling some periodic autosave should be possible...+Running `./build.sh` from the repository root should build the `xrxs` executable.
+
+You can run a local server (for testing, split-screen games, or single-player games) with:
+```
+./xrxs -m /path/to/mountpoint
+```
+
+or expose a service on the network (uses `9pserve` to support multiple users and gracefully handle disconnects) with:
+```
+./xrxs-srv.sh start
+```
+
+Similarly, you can stop the service with:
+```
+./xrxs-srv.sh stop
+```
+