Today during the Alonzo White testing phase the Cardano team made important progress as they successfully compiled and ran their entire application back-end in java-script!
As the team polish and optimize this functionality it will eventually enable Plutus applications in your browser. As of today to interact with the Cardano network it is necessary to use the Daedalus or Yoroi wallet or an exchange, but once all the Alonzo phases are complete any web developer will be able to write their own browser applications that uses the Cardano network as a database.
Charles Hoskinson has been very busy, at the start of his recent video he talked about the state of the current development:
On the 29th of July the next Cardano 360 episode will air and you'll be able to get more detailed descriptions of the current situation.
Alonzo is being broadened to more people, going from dozens to hundreds that will test out the network with seven different programming exercises.
Some research papers that Charles is enthusiastic over and is pushing to get implemented will allow for clients with high security and fast validations of prior epochs. Light weight clients that won't be as cumbersome as Daedalus but allow for complete trustlessness unlike Yoroi, allowing for easy access to the Cardano network through browser and cellphone.
All updates require participation from over 100+ integration partners, like exchanges and wallets since Cardano does this updates from hard forks. But with a clear timeline and good partners there seem to be no issue in this area.
There has been no significant delays in any Alonzo phase so far and at the speed of testing it seems that the full release of smart contracts will be somewhere within August or September.