Well, recently Google released a new tool in their beta labs to track trends in searches www.google.com/trends. While Alexa tries to rank traffic to a site (with people that have their Alexa toolbar installed), Google is simply querying its database to show a trends for a particular search term.
Firstly, the tool is immensely useful. If you have a site that is in any way connected to business, you should be identifying your keywords based on traffic volume and then analyzing them for trends. If a particular keyword phrase is dropping, you should shift your linking campaign to ones that are growing in search volume. In short, Google Trends allows you the previously unavailable dimension… time. This result compares “Joomla’ and “Mambo”. Its also worth noting that the Mambo searches include ones for the dance and the group!
Secondly, it sort of affirms the post I made previously about the health of Joomla and Mambo.