Open or create a program:
create a new file (File->New or CTRL-N)
open a file via FileBrowser ( File->Open.. or CTRL-O + double-click file)
Save a program:
save a file(File->Save or CTRL-S)
save all opened files (File->Save all.. or CTRL-SHIFT-S)
save as (File->Save as.. or CTRL+ALT+S11)