Scollector supports tcollector style external collectors that can be used to send metrics to Bosun via custom scripts or executables. External collectors are a great way to get started collecting data, but when possible it is recommended for applications to send data directly to Bosun or to update scollector so that it natively supports additional systems.
The ColDir configuration key specifies the external collector directory, which is usually set to something like /opt/scollector/collectors/ in Linux or C:\Program Files\scollector\collectors\ in Windows. It should contain numbered directories just like the ones used in OpenTSDB tcollector. Each directory represents how often scollector will try to invoke the collectors in that folder (example: 60 = every 60 seconds). Use a directory named 0 for any executables or scripts that will run continuously and create output on their own schedule. Any non-numeric named directories will be ignored, and a lib and etc directory are often used for library and config data shared by all collectors.
External collectors can use either the simple data output format from tcollector or they can send JSON data if they want to include metadata.