I am using vqcc-0.5 in my chat in order to chat with other users on my netowrk. Most users use Vypress chat in windows so I think there is no variant better than vqcc in linux in order to chat with them. But there are some users who use linux. which chat program do you recommend me use in order to chat with linux users in my LAN?

I like Ekiga, they just released 2.0 version, try it out.
http://www.ekiga.org/

rpm -ihv ekiga-2.0.1-1.i386.rpm
warning: ekiga-2.0.1-1.i386.rpm: Header V3 DSA signature: NOKEY, key ID de95bc1ferror: Failed dependencies:
libopal_linux_x86_r.so.2.2 is needed by ekiga-2.0.1-1.i386
libpt_linux_x86_r.so.1.10.0 is needed by ekiga-2.0.1-1.i386
opal >= 2.2.1 is needed by ekiga-2.0.1-1.i386
pwlib >= 1.10.0 is needed by ekiga-2.0.1-1.i386

How to install opal and pwlib? I have downloaded the tar file and extracted but don't know what to do with it

In the tar files, look for a README or INSTALL file. They will tell you what to do. Most likely you need to "./configure; make; make install" to compile and install them.

There is no file for configuring and making the library.
when I extract tar file, I get 2 directories:
first one is called installed and has a file called doinst.sh which cannot be run by ./doinst.sh

the second directory is called usr. It consists of 4 subdirectories:
doc,include,bin and share.
inside the lib there exists this library libopal_linux_x86_r.so.2.2.1.

I guess I have to link or copy this directory to another directory.

I tried to install pwlib-1.10.0 on my fc4 machine which has pwlib-1.8.4-1 installed on it.

but installation of these 2 libraries are alike.

I would be glad If anyone helps me,

That seems to me like you got Slackware install package but I might be wrong since I haven't used slackware so much(Gentoo user ^^)

I am going to install opal-2.2.1-i486-1kjz.tgz and pwlib-1.10.0-i486-1kjz.tgz.
I don't know what 1kjz means