Latest project is available at the main page of the device. In the wiki one can only find older projects, that still might be helpful. These projects are no longer officially supported. The best practice is to use the EXACT same compiler as mentioned and in most cases the exact same MPLAB version as mentioned.
Older projects released by Olimex for PIC32-MAXI-WEB:
1) PIC32-MAXI-WEB v1.01 for MPLABX 1.10 and XC32 1.20 (old) - https://www.olimex.com/Products/PIC/Development/PIC32-MAXI-WEB/resources/DemoSoftPIC32-MAXI-WEBv1_01.zip
2) PIC32-MAXI-WEB v1.01 for MPLAB 8.xx and C32 1.10B (old) - https://www.olimex.com/Products/PIC/Development/PIC32-MAXI-WEB/resources/DemoSoftPIC32-MAXI-WEBv1_01.zip
1) An interesting project in Thai language - http://www.10logic.com/microcontroller/microchip-tcpip-stack.html