Hub list is empty. Help!
This means that Sharelin couldn't connect to any hub in it's list and have deleted all of them. It can occur if you lose a connection to Internet for 10-15 minutes. Copy "hub_cache" file from sharelin release to sharelin folder and restart it.

Does Sharelin support original Gnutella or other nets
No. Only Gnutella2 (G2).

How can i reduce CPU usage
High CPU usage occurs when there is a file hashing in progress. You can alter it's speed by changing "Hashing rate" option in webui or "HashRate" in sharelin.conf . Set 1 for minimal speed. 0 is unlimited. You can increase speed by setting 2, 3 and so on.

Is Sharelin based on Shareaza?
No. Similarity of the names is a coincidence. "Sharelin" is made from "Sharlin" which is a type of Minbari warcruiser (pretty powerful by the way, see it yourself). Sharelin was written from scratch. Some code (hashing, base16/32/64) encoding is borrowed from various sources, but it is always with GPL (or compatible) license. Only QuerryHashTable is from Shareaza. Socket class is partly from Mutella. Sharelin was planned to be a G2 BSD/Linux uploading-only client to support G2 network and particulary Shareaza application after domain takeover. Sharelin was friendly accepted by Shareaza community and until pantheraproject.net was hijacked, had subforum on official Shareaza forums. Currently Sharelin uses forums provided by SF.

Is there a chat?
No.

Does it handle big files (several GB)?
Yes.

Does Sharelin support UTF-8
Not yet.