If all what you need is a list of nautilus related packages, you can get it very easily with:

$ dpkg -l | grep nautilus


E.g for me it returns:

ii  gir1.2-nautilus-3.0                                   1:3.10.1-0ubuntu9.2                                 amd64        libraries for nautilus components - gir bindings
ii  libnautilus-extension1a                               1:3.10.1-0ubuntu9.1                                 amd64        libraries for nautilus components - runtime version
ii  nautilus                                              1:3.10.1-0ubuntu9.1                                 amd64        file manager and graphical shell for GNOME
ii  nautilus-data                                         1:3.10.1-0ubuntu9.1                                 all          data files for nautilus
ii  nautilus-open-terminal                                0.20-1                                              amd64        nautilus plugin for opening terminals in arbitrary paths
ii  nautilus-pyextensions                                 3.0-1                                               all          Handler of the Nautilus Python Extensions
ii  nautilus-sendto                                       3.6.1-2ubuntu1                                      amd64        integrates Evolution and Pidgin into the Nautilus file manager
ii  nautilus-sendto-empathy                               3.8.6-0ubuntu9.1                                    amd64        GNOME multi-protocol chat and call client (nautilus-sendto plugin)
ii  nautilus-share                                        0.7.3-1ubuntu5                                      amd64        Nautilus extension to share folder using Samba
ii  python-nautilus                                       1.1-4                                               amd64        Python binding for Nautilus components
ii  seahorse-nautilus                                     3.8.0-0ubuntu2                                      amd64        seahorse plugins and utilities for encryption in GNOME


Trying to guess which ones are plugins or extension is a bit more complex:

dpkg -l | egrep -i 'nautilus.* (extension|plugin)'


This time it returns:

ii  nautilus-open-terminal                                0.20-1                                              amd64        nautilus plugin for opening terminals in arbitrary paths
ii  nautilus-pyextensions                                 3.0-1                                               all          Handler of the Nautilus Python Extensions
ii  nautilus-sendto-empathy                               3.8.6-0ubuntu9.1                                    amd64        GNOME multi-protocol chat and call client (nautilus-sendto plugin)
ii  nautilus-share                                        0.7.3-1ubuntu5                                      amd64        Nautilus extension to share folder using Samba
ii  seahorse-nautilus                                     3.8.0-0ubuntu2                                      amd64        seahorse plugins and utilities for encryption in GNOME


How can I find out what plugins I installed for Nautilus?
When you add an image to a post via the helper bar, you get this:

![enter image description here][1]

[1]: http://i.stack.imgur.com/ve8n0.png

What purpose does the enter image description here text serve? I've not noticed anyway of seeing this text, except if I view the page source for the post.
