You don’t need any software to download you tube videos in Linux… Just follow these steps and enjoy the flvs
Step 1. Open the required video in the web browser.
Step 2. Let it start streaming/buffering.
Step 3. Minimise the window and open /tmp.
Step 4. Look for a file flash
Step 5. Drag the file on to your desktop.
Step 6. Once the video is buffered in the browser, the file would have been downloaded.