Collect logs from hosts - free syslog server

Do you know any software which can collect logs from LAN servers and show them in clear and managed form? It generally should works with linux clients (Windows is optional).
I was trying Kiwi syslog solarwinds.com/products/kiwi_syslog_server/features.aspx , but as I know (meybe I'm wrong) it use only snmp for linux servers - it can't send system logs.
For monitoring I use Munin.
Second one, which I was trying is php-syslog-ng but it is only local (non network) and very old project (2004).
It would be best if it can run scripts on incidents and have a web access interface and database MySQL.
I'm lookking for something free - for example Kiwi syslog is free in limited/poorer version after trial period.

The enhanced syslogd for Linux and Unix rsyslog
together with
phpLogCon :: a syslog data viewer for the web
should meet your requirements.

For a start, all clients only need the standard syslog daemon, and even windows can log in that protocoll.

So only the syslog server should be rsyslog.

collectd may serve you well?

depending on how many clients you have Splunk | IT Search for Log Management, Operations, Security and Compliance has a free version and their interface is one of my favorites in any free or enterprise log manager.