How to install NuGet addin for MonoDevelop?

Steps:

1. Start the Add-in Manager by clicking on the Add-in Manager option in the Tools menu.
2. Click on the Install Add-ins button.
3. Click on the Repositories button.
4. Click on Add.
5. Enter http://mrward.github.com/monodevelop-nuget-addin-repository/4.0/main.mrep
6. Click OK and then Close to go back to the install dialog.
7. In the Install From combo box select either All registered repositories or the NuGet add-in repository.
8. The install dialog shows a list of available add-ins. Only add-ins which are not installed will be displayed.
9. Select the add-ins (NuGet) you want to install (use the check box to select).
10. Click on the Next button.
11. Verify the list of assemblies that are going to be installed.
12. Click on the Next button to proceed with the installation.

Sources: Google: ubuntu monodevelop nuget --> First hit --> Follow link in Getting the Addin section

201501: Just tried this and it seems to work differently now:

1. In Mono open Add-In Manager
2. click the Gallery tap
3. in the Repositories drop down, click "Manage Repositories"
4. add the above http://mrward.github.com/monodevelop-nuget-addin-repository/4.0/main.mrep URL, close "Manage Repositories",you should now see a NuGet entry under IDE extensions (in the Gallery), install it
5. the access to the Nuget Package Manager is now under the right click menu of the project name or under Project menu from the top level.