HotJava是一个模块化、具扩展性的网页浏览器，由升阳电脑所推出，并且可在网页中运行小型的Java程序（称为Java Applet）。

事实上，甲骨文公司在1995年发表了Java编程语言后，由于当时的网页浏览器多数只能浏览网页内的静态数据，如文本、表格、图形等，尚无法在网页中运行程序，而升阳电脑希望让Java程序成为浏览器上最普及使用的程序，初期特别是积极于容量小，容易在带宽有限的互联网上传输、下载的Java Applet，而当时多数的浏览器尚无法支持与运行Java Applet，以致升阳电脑率先示范，推出可支持运行Java Applet的网页浏览器：HotJava，更早之前有一小段时间称为WebRunner。

HotJava (later called HotJava Browser to distinguish it from HotJava Views) was a modular, extensible web browser from Sun Microsystems implemented in Java. It was the first browser to support Java applets, and was Sun's demonstration platform for the then-new technology. It has since been discontinued and is no longer supported. Furthermore, the Sun Download Center was taken down on July 31, 2011, and the download link on the official site points to a placeholder page saying so.