You can delete it if you want, it does not hurt other projects. It is created by the remote system explorer that comes with Eclipse.
To prevent it from being rebuilt (in a new project), turn this option off: In Window- > Preferences type ' Remote '. Click 'Remote Systems View and uncheck ' Reopen Remote Systems View to Previous State ' Previous). Note: This option worked for me
Another option (if it does not work)
Just go to Window - > Preferences - > General - > 'Startup and Shutdown' and uncheck RSE UI . Then you can remove the folder and Eclipse will not re-create it.
Post that helped me (at the time)
What is RemoteSystemsTempFiles in Eclipse?