Yes, they can. Besides using a standard browser (which should be a viable option on IPad), there are some custom clients written for mobile platforms:

Yerbabuena's client: http://blog.yerbabuenasoftware.com/2010/05/open-source-mobile-clients-for-nuxeo.html

Nuxeo's prototypes: http://code.google.com/p/nuxeo-webengine-mobile/ https://bitbucket.org/sfermigier/nuxeo-mobile-web

yes applications based on Nuxeo Platform can run on iPhone and iPad, two options:

• via a web application that could be optimized for the iPad or iPhone (this means user will go in a browser to access the application)
• via a client application that needs to be installed on the iPhone or the iPad

In the first case, web application: this is pretty simple, it just needs the user interface to be optimized. Developing the user interface with Web Engine is a good way to go. Nuxeo is developing a generic mobile version of Nuxeo DM available here: http://code.google.com/p/nuxeo-webengine-mobile/ This is still early stage and beta. Another prototype using JQuery here: https://bitbucket.org/sfermigier/nuxeo-mobile-web

In the 2nd case, client application: you would need to develop an application for iOS that for instance uses REST or CMIS APIs. Nuxeo might provide something in the future even if priority has been given to the Android system. There are also some initiatives in the community such as Yerbabuena's client: http://blog.yerbabuenasoftware.com/2010/05/open-source-mobile-clients-for-nuxeo.html

here is the Github code for NUXEO iOS: https://github.com/nuxeo/nuxeo-iphone but you have to download and compile it on you own