How can we convert extensions designed for Joomla 1.0 to work with Joomla 1.5 in native mode?

You need need to modify the code and the old instructions, and can be very useful to refer to this reference written by Andrew Eddie.

Are treated different topics including the editing:

• Changes to the functions of the template
• Global Variables
• API changes in the functions and main
• Database
• Components
• Manage the administration menu
• API to access the cache
• HTML Helpers
• Toolbar and Menu
• Plugin
• File formats

Truly an excellent and comprehensive guide, very useful now that there a few months till the end of official support for Joomla 1.0.

In this way it will be possible without too many problems extensions for Joomla 1.0 that you may have been abandoned by their creators, although the ideal would be to rewrite so that exploit the architecture introduced by the MVC Framework in Joomla 1.5.