At first word I like to thank for all who helped me with this project . 
That project was born by two accidents - first I had lost in air and crash my FPV RCmodel , second I ordered OSD samples from maxim and when they arrive at evening for fun I wrote small software for display some letters on TV .
After that I thought about need for nice , light-weight , small and cheap OSD unit , so that is it .

Project is under TAPR open hardware licence - so first download and read LICENCE file .
In one word - any manufacturing and sales without permition of author is not allowed .
I do not sale on ebay .

Lastly a lot various remzibiOSD are available on ebay and some internet China's shops - they are white or similar looking green boards.
Those are China copy of mine design , I do not support them and I am not responsible for any problems, malfunctions and services.
Those copy sales against licence terms , as I do NOT agree to manufacture and sale them.
Those copy sellers do NOT support me or my work at all . 
The main reason why anything is copied - is that ORIGINAL IS GOOD .
Everybody knows China and their copy talents - so conclusions are Yours .
About the clones you can read RCGroups RCG2 RCG3 RCG4

OSD unit must be fully controlled by user regards to showed information , screen interface layout and message labels . 
As many living projects , must be easily software updated by end user , new or alternate software as well as OSD chip character/semi-graphics also configurable and updated by end user . For that need , communication USB-UART device is included (called USB cable) . 
To meet the cheap requirement , for now are not used any current sensor (however possible to connect any kind of such sensor) , the voltage indicators only . 
More sensors can be added as some free inputs are designed on board . 
Final price must be around 100$-120$ including all set (OSD unit , GPS module , USB communication unit) , what is done . 

Unit must proper work with any GPS module with any fix update (1-10Hz) and communication baud rate speed automatically detected .
However build in configuration commands are optimized for MTK modules , also Ublox are supported if configuration command will be modified .

If anyone decide to build the unit by his self , it is also possible what was proven by our friend who has naked PCB only and successfully finished his device adding all parts and chips . 

The hardware base is MAX7456 OSD chip controlled by micro controller MEGA16 by SPI bus , GPS module connected to unit provide all needed information about latitude, longitude, speed, altitude, course, based on that information and saved Home position , OSD calculate main information like Home-course and Home-distance , what help any pilot to return home during flight - what is a main function of this OSD . 

I didn't want to occupied any RC channel , so for work OSD do not need any of them (possible use with any 3 and 4 channel simple radio TX) , there is only one switch/button on OSD unit , used to Home position save . 
The other function of this button is to change video mode from NTSC to PAL and PAL to NTSC , this modes are difference with screen grid resolution NTSC-30x12 PAL-30x16 and must correspond with video camera used in video system . 
The video mode is saved at first Home position save and OSD start(after power-on) with selected(last saved) video mode .  

All screen layout configurations/calibration changes can be done on PC computer and then programmed into OSD unit by  USB cable .  Software (GUI) for this is still in development .

Schema and software files are available for download .

Technical data :
- Supply power : 7V-14V (ex. lipol 2S - 3S)
- video voltage measurement range 0-15V
- engine(ENG) voltage measurement range 0-30V
- general purpose ADC measurement range - any range depended from resistor dividers or used opamps (maximal input voltage 5V) .
- Video signals - standard PAL or NTSC (both working very well)
- GPS - any GPS 5V supply , NMEA protocol , TLL standard TX RX signals (however best results and advantages are with dedicated GPS module working 1-5-10Hz update position configurable)
- weight : 18 gram (OSD + dedicated GPS + cables)
- printed board size 20mm x 45mm  

Functionality :
- easy PC connection for configuration/calibration purposes using dedicated PC program , GUI was wrote by Paul (Ohio, USA , nick HappyKillmore)  excellent work
- no RC channel occupation for proper work  
- GPS detection and configuration automatically (configuration commands fully editable) 
- auto "Save Home" function configurable , depends on sat number , button "Save Home" works independently 
- metric (km/h) or feet (mil/h) units - configurable
- zero altitude to airfield level - configurable (absolute or relative)
- fully configurable screen layout  
- graphical symbols and fonts configurable (possible exotic languages , fully editable font table)
- voltages calibration function for all ADC inputs including alarms  
- frequency measure and calibration for Hz or RPM or whatever else we want to use , at input T0 (max input 5V) (pull up resistor inside chip enable)   

button function
- save home position (short click) (work only when GPS is detected)
- video mode change (NTSC or PAL) press and hold button for about 2 seconds (work only when GPS is detected)
- configuration mode for USB communicate with PC (pressed and hold button, then connect power , font pattern on screen will appear)

show information DONE  :
- latitude  (display format DDMM.MMMM or DD.DDDDDD can be selected)
- longitude  (display format DDMM.MMMM or DD.DDDDDD can be selected)
- speed  (k/m or miles/h can be selected along with meter or feet)
- altitude  (meters or feet)
- to-home course/direction  (animated arrow or whatever else animation definable by user at font table)
- to-home distance   (meters or feet)
- satellites quantity   
- video battery voltage   (individually scaled and calibrated)
- main battery voltage    (individually scaled and calibrated)
- flight timer   
- variometer   (speed of climbing/falling) (meters/s or feet/s) 
- UTC Time
- UTC Date
- alarms for distance , ADC values , altitude , battery voltages (individually scaled and calibrated)
- 32 static displayed independent graphical-character symbols (sprites) , configurable
- after detection 0 speed for configurable X seconds , shows maximal values for altitude , distance , speed collected at flight, function can be off
- 6 ADC channels to use with any additional sensors , each ca be individually calibrated , scaled and alarm set, cooperate with any additional sensors (optional scaled by opamp or resistor dividers) with analog output (RSSI , current sensor , temperature , whatever else with analog output) , configurable display format as 123 or 123.4 can be selected
- frequency meter (old PCB RCI input, resistor 220-515ohm must be added) , at new PCB is T0 input - can be scaled for any needs by gain , can work as Hz or RPM , cooperate with magnetic(hall effect sensor, hallotron) or optical sensors - or can be used as frames counter when connected to RX channel output directly
- OSD have support for $M custom messages command - for those who want to display his own text or fonts(graphics) anywhere at OSD display , $M can be transmitted between $GPGGA and $GPRMC GPS strings by "your device" , or when GPS is not detected simply display any text or fonts from font table 
- since OSD's 1_77 firmware, GPS configuration support MTK as strings and Ublox as binary modes for GPS modules 

Every displayed information can be placed everywhere on screen, can be switched on or off, has definable leading character(or picture) and ending character(or picture)
All configuration is done by PC configuration program (GUI) wrote by HappyKillomore (great job, program is really very good)

- firmware OSD versions for cooperation with other projects or devices like Ardupilot , also graphical presentation of artificial horizon , pitch and roll or pitch+roll mixed . That firmwares keep all advantages of regular OSD , as ADCs , custom graphics , $M custom messages to display any text you want . Added for download a PC program to test OSD behavior - emulating all commands of external device .
- version of firmware supporting external devices cooperation , use custom protocol (described in readme.txt at firmware pack) , here is very good thread done by HappyKillmore about integration with Ardupilot  

- lastly made firmware added support for Artificial Horizon in regular OSD , where input for software RX are done on T1 input (still in development)  05. Artificial Horizon(AH) at software emulated RX input  

- work with FY30A stabilizer , it provide AH data so remzibiOSD can display Artificial Horizon based on those data .
Firmware for OSD to dowload here

- work with FY90Q quadrocopter control , it provide AH data so remzibiOSD can display Artificial Horizon based on those data .
Firmware for OSD to dowload here

- work with FY21AP and FY31AP autopilot , remzibiOSD serve as display for FY21AP data.
Firmware for OSD to dowload here

- telemetry data downlink, based on reading on-screen data, it is very nice project, worth to see.


- somehow adding cooperation with MultiWii new protocol
- MAVlink implementation to work with APM2
- any ideas in future

Configuration GUI program for download here - 

so anyone who want to play with OSD ability, can simply install it on PC and try without buying OSD, what in fact is recommend .
Here is the English help web side
- still in development  
All new version of PC software are simply updated by internet , include new OSD firmwares files as well as new Font files and eeprom (BIN) , USB drivers etc. 

Also latest software and firmwares are available to download from this web side .
Here is the thread with some more technical information and tips(like connecting current sensors , temperature sensors , RPM sensors etc.)

Here is manual written by Ralf  Homering (Germany), I hope will help for many to understand OSD bases.
Please view manual at bottom of this side or at Downloads