- In the dns directory there's an example of how to write a DNS clientusing  ares  and RTL-lwIP.   - In the raw_api  directory there's an example  of how to use the  rawAPI.- In the sequential_api directory there  are some examples showing howto use the sequential  API. Particulary, the  tcpclient example in thetcp_echo   subdirectory  also shows   how  to use  sys_thread_registerdespite of sys_thread_new.- In the sockets_api directory you'll find a TCP echo client using thesockets API.RTL-lwIP home page:http://www.rtlinux-gpl.org/~serpeal/RTL-lwIP/htmlFiles/index.htmlPlease send comments to Sergio Perez <serpeal@upvnet.upv.es>