From the author:

Information

So what is this about? Well, it basically gives you an additional monitor with a 960x544 resolution (four times the area of the PSP display). There are four components working together, on Windows a display driver, an usb driver and the interface application which captures the screen, compresses it and sends it over USB to the PSP. On the PSP side there is an application that decompresses the frames and displays them. All settings are adjustable from the Windows side, the PSP really only acts as a passive display.
Requirements

PSP: Either slim or phat model running a custom firmware (tested on CFW 4.01 M33).

PC: Reasonably modern PC (Pentium 4 / Athlon64 or above) running a 32 Bit version of Windows XP. It may work under Windows 2000, but it is untested. 64 bit versions are not supported, as well as Windows Vista. I would like to provide a Vista version but it will probably never happen due to the changes in the display driver model regarding multi-monitor support.
Installation

Windows application, drivers, etc.
# Download the installer below and execute it.
# When it comes to the display driver installation, Windows will warn you that the driver is unsigned, let the setup program install it anyway.
# After setup has finished, open your display settings and enable the new monitor then move it to the position you like.
# Connect your PSP and copy the files from the "psp" folder in the installation directory to the memory stick.

Compiling the source

The whole project needs three different compilers / IDEs, fortunately all of them are available for free on the net. Note that the setup process for them will take a while and is rather involved.

The display driver needs the Microsoft WDK (Windows Driver Kit).

Building the Windows application requires Borland Turbo Delphi.

The PSPSDK (PSP toolchain) is needed for compiling the Playstation Portable application. I use the PSPSDK for Windows.