Differences with Smart and Web Client, compatibility wise:

• onRender is not longer possible, webcomponents are outside servoy's control we cannot enforce behavior onto them
• webdav feature for WebClient is lost due to incompatibility with Tomcat 8 server used inside Servoy
• printing a form from scripting is not possible, browser printing needs to be used or jasper reports for reports
• client design is not present (yet)
• beans depending on technologies such as Java Swing or Apache Wicket will not function
• A much used plugin called webClientUtils from ServoyForge is not supported, since it depending on Apache Wicket
  
  

Small tablefilter behaviour change

The behaviour of databaseManager.getDataSetByQuery(QBSelect, int) changes behaviour. Before release 8.0 this call will not take table filters into account, but in v8 release the filters will be applied. The method databaseManager.createDataSourceByQuery(QBSelect) will use table filters, both in older versions and in the new release. Both methods have a new optional  boolean argument to explicitly use or skip table filters.

Changes to StyleSheets usage

For the NGClient the limitation of only being able to use CSS properties that Servoy explicitly supports in StyleSheets has been lifted, any CSS property can now be used. Instead of preprocessing the stylesheets authored by the developer before sending it's content to the browser, the only preprocessing that now takes place is expanding syntax to browser specific syntax.

This change has the following behavior changes:

1. Stylesheets can't be set anymore on Forms, but only on Solution level
2. Only one stylesheet can be assigned on Solution level
3. Additional stylesheets can be included using the @import statement in the main stylesheet
4. Inherited CSS properties (see http://stackoverflow.com/questions/5612302/which-css-styles-are-inherited) set on a Form will also affect any Forms contained in containers (TabPanel, SplitPane, Accordion etc.) 
5. When different stylesheets are included that utilize the same classnames, the CSS properties set in the classes are merges and incase of duplicates, the last one wins