This research is to develop the multiuser collaboration infrastructure which enables multiple users to interact and collaborate on host applications using their mobile devices. Multiuser collaboration is an important element of ground operations in planetary rover and lander missions. During mission operations, scientists need to meet often to plan science activities with planning and visualization tools projected on large displays. This infrastructure will allow the scientists to interact directly with the software tools to collaborate on science planning activities. The infrastructure includes (1) human-computer interaction techniques that enable natural, fast, and accurate inputs, (2) application-independent middleware that maintains information about the connection, state, and session of individual users and enables interaction and collaboration with the software applications, (3) communication protocol that ensures reliable and secure connectivity between the mobile devices and host computers, (4) toolkit that generates GUI components that can be displayed on mobile devices, and (5) delivery and synchronization services that transport application components and data for offline interactions. The infrastructure supports a broad range of mobile devices encompassing laptops, PDAs, and cellphones, and supports all desktop applications running under the Windows or Unix platforms.