Is the appian community site developed with appian?

The community is not built using Appian.

Is this what you are looking for?

https://docs.appian.com/suite/help/21.4/fnc_scripting_a_isPageWidth.html

docs.appian.com/.../responsive_design.html

Thank you!!

Hi,

As the other commenter mentioned, the community site is not built using Appian but you can manage your screen visuals using the provided function. 
About the mouse hover, you cannot trigger actions on the mouse hover, rather only show some help text, also known as caption or tooltip, to a user. 
These captions/tooltips are not available for every UI component but you can find them in most of the places where you need them. 

I am not sure about what are you really referencing to by 

dreamyoung said:

It seems that some advertisements have been posted on the bulletin board. Think that it needs management?

Appian is a B2B and/or B2G  low code development platform.
It is a new fast, flexible and lean way to develop applications for company internal use. Easy adjustable for new requirements if necessary.
You are limited to the appian provided functions and appian specific extensions made by plugins as you need the platform to execute it. 

Get webshops, websites, games etc out of your mind. That is a complete other part of the world of programming.
It is not a website or mobile app builder...

Thanks for the reply.
Is this answer based on your experience? Or is it the official position of appian?
Will Appian go beyond B2B and B2G to more advanced development in the future?

I am working with appian since january 2018. So i have solid base how to use and implement appian.
that is pretty officially and even asked during certification exams ;)  

dreamyoung said:

Will Appian go beyond B2B and B2G to more advanced development in the future?

 No, three reasons for that.
1.) That will be difficult as you need always the platform to execute the appian functions.That is the core part of appian business model. Steady income with licences for that platform.
2.) The platform is based on BPMN (meta) processes and "views" on data like reports or specific (structure) type of data like "records" and so on. So it is waaay more than the a!- functionalities.
3.) On top appian itself is based on java. As long as appian is not extending java functionalities, there won't be any similar thing.
4.) The idea is: be faster than "advanced development" languages so you need less budget and you are more flexible to react to necessary changes. But to archive that, there will be always compromises. Appian tries to be champion in its specific area