I have a software doing ftp that perfectly works with PCs directly connected to the internet but it is unable to perform connections to the server when run at one of my customer's office. I suppose this is due to his office LAN settings that will block FTP port. I cannot ask him to have those settings changed. On the other hand he is perfectly able to do HTTP file transfer. I guess what I need is a free C library that would allow me to do HTTP file transfer. Or any other free library that will solve my problem.