Solution 1:

For development in python:

Update for 12.04:

Unity lens development with singlet has been integrated into quickly:

quickly create unity-lens <lens-name>

For 11.10:

You might want to look at a very nice wrapper class developed by Michael Hall called singlet: https://launchpad.net/singlet

A simple hello world lens would look like this:

#! /usr/bin/python
from singlet.lens import SingleScopeLens, IconViewCategory
from singlet.utils import run_lens

class HelloWorldLens(SingleScopeLens):
    class Meta:
        name = 'helloworld'

    cat1 = IconViewCategory("Cat One", "stock_yet")

    def search(self, phrase, results):
        results.append('http://google.com/search?q=%s' % phrase,
                             'file',
                             self.cat1,
                             "text/html",
                             phrase, phrase, '')
if __name__ == "__main__":
    import sys
    run_lens(HelloLens, sys.argv)

Which is a lot simpler and faster to write than the original library versions.

Solution 2:

Yes it is absolutely possible and really easy to create new scopes. The Ubuntu App Developer site has lots of content to get you started writing scopes:

  • Scopes overview
  • Tutorial: Writing a scope
  • Scopes cookbook

Solution 3:

The Ubuntu Wiki has a tutorial on how to write a Lens that uses Vala. Saravanan Thirumuruganathan wrote one for Python. The Unity Sample Place has some simple example lenses written in python and Vala.

As far as I know it's not (yet?) possible to write lenses in PHP.

Solution 4:

There are a bunch of tutorials in the Ubuntu Lens wiki. The easiest I think is one I found on a blog here.

Here is the wiki.