What is spcaserv/servfox ?

Spcaserv or Servfox are streaming servers to used in conjonction of the spca5xx spca5xx-LE module
Spacserv is the more generic one and work on x86 embedded machine.Spcaserv support the whole set of spca5xx webcams and provide a jpeg compressor, no external library are need to compile the package. The parallel port is used as Input Output lines and can be set by the client side to command servo, motors, relays, Pir detector and so on.
Servfox is set for the embedded Foxboard and can be used on the Arm9 board to:) Only the subset of webcams used in the spca5xx-LE package can run . The Foxboard or the Arm9 provided usefull set of I/O lines and can be used for i2c chips like the SD20 or SI2C20 from the pic familly to command 20 servos motors,Real times clock, AD DA convertor, motors, Ultrasound, Pir, IR detectors.

What is protocol between Client and Server?

When a Client connect it send a short message to the server asking for a frame.
Then the Client go to sleep waiting for a frame header.
The server is waiting and read the short message
If the short message is OK it send a frame header over TCP to the client
Following by a whole compressed frame
When the Client get the header it will ask for the corresponding frame
receive the frame and go back to the short message sleeping.
This is a closed loop protocol, with bidirectional exchange. Client can then command the remote server for the video stream parameters but also read or write the remote GPIO pins.
The server side is multithread so many client can connect to the server in real times. The server have a ring buffer of fresh frames in memory and can then provide video streaming without buffering :)
It should be simple to add a custom lock in the closed loop protocol to provide better security.
The client/server protocol allow the client to sleep until an hardware event comes trought the GPIO lines.

How can i run spcaserv servfox ?

There are a README file in the package to know all parameters setting.
spcaserv -h or servfox -h give you usefull informations to :)

servfox -d /dev/video0 -s 320x240 -w 7070
run servfox on the first video node available with 320x240 framesize and listen to port 7070
spcaserv -d /dev/video0 -f yuv -s 352x288 -w 7070
run spcaserv on the first video node with a frame size of 352x288, palette yuv420p, listen on port 7070

to get the server working in background the & operator can be used :)

Where can i find schematic to used the GPIO lines

Soon here, but fill free to mail your's I will set up here :)