RTL8139 support drivers for the following Real Time OS :
1. VxWorks     : under development
2. pSOS        : under development 
3. EmbededNT   : Ready 
4. WinCE       : Ready
5. JavaOS      : Ready
6. QNX         : Ready
7. BeOS        : under development

Please refer to Realtek's Website :
        http://www.realtek.com.tw/cn/driver/8139-driver.htm