When comparing Ambassador vs Quassel, the Slant community recommends Quassel for most people. In the question“What are the best IRC clients for Windows?” Quassel is ranked 7th while Ambassador is ranked 27th. The most important reason people chose Quassel is:
Quassal is available for free with source code licensed under GPL and available [here](http://bugs.quassel-irc.org/projects/quassel-irc/repository).
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Wrapping IRC client inside web browser provides natural workflow
So much of the purpose for any interpersonal communication is wrapped up in exchanging knowledge and sharing experiences with IRC being no different. The modern era has taken us to a place where a large portion of what we want to share and exchange with others are things which require the internet and a web browser, so when links are inevitably traded on IRC, the ability to interact with them natively in another tab of the same application has become one of the most productive ways to use IRC.
Pro Free and open source
Quassal is available for free with source code licensed under GPL and available here.
Pro Distributed
It's possible for a front-end client or multiple front-end clients to connect to a single core client. This allows setting up an always on-line core that can be accessed from anywhere.
Pro Easy installation on Ubuntu due to the existence of PPA's
Right now Quassel has a PPA maintainer, which allows you to install the stable version or daily versions.
Support for PostgreSQL as database backend and easy to configure for people that know a bit about systems.
Cons
Con Potential memory bloat in monolithic client if left running for a period of time
(I don't know if this problem has been fixed in recent years, but I have doubts)
Con No DCC support
DCC or Direct Client-to-Client protocol allows for private communications between users (without the traffic being routed through servers). Neither chat nor file transfers are supported.