Flow is H₂O's web client.

Install Node.js

brew install node

To install development dependencies and build the web client, run the top-level gradle build:

cd /h2o-dev
./gradlew build -x test
java -jar build/h2o.jar

And then point your browser to http://localhost:54321

First, install Node.js by following the instructions on the Node.js wiki

To install development dependencies and build the web client, run the top-level gradle build:

cd /h2o-dev
./gradlew build -x test
java -jar build/h2o.jar

And then point your browser to http://localhost:54321/

Install Node.js using the official installer. When done, you should have node.exe and npm.cmd in \Program Files\node\. These should also be available on your PATH. If not, add the folder to your PATH.

Run the top-level gradle build:

cd /h2o-dev
gradlew.bat build -x test
java -jar build/h2o.jar

And then point your browser to http://localhost:54321/