1. A non-transitory computer-readable storage medium having computer-executable instructions stored thereon that, if executed by a processor of a computing device, cause the computing device to perform actions of server-side components to create a new file in a group folder that is accessible to multiple client computing devices, the actions comprising: receiving a subscription request from a first client computing device to mount the group folder locally and listen for changes in the group folder; adding an object that represents the group folder to a subscription list associated with the first client computing device; receiving a file creation request from a second client computing device to create a new file in the group folder; allocating space for raw file data in a storage location; instructing a folder database to create an entry for the new file and associate the raw file data in the storage location with the group folder; determining that the first client computing device is listening for real-time changes to the group folder by locating the subscription list associated with the first client computing device in a message chain associated with the group folder; and in response to receiving the file creation request from the second client computing device and locating the subscription list associated with the first client computing device in the message chain associated with the group folder, causing a transaction to be transmitted to the first client computing device, the transaction configured to cause a view of the group folder mounted on the first client computing device to be updated to reflect creation of the new file in the group folder by the second client computing device.
6. The computer-readable medium as recited in claim 1 , wherein a semantically defined application executing on the second client computing device causes the new file to be created to initiate a chat session between group members.