Vector Markup Language (VML)
Definition - What does Vector Markup Language (VML) mean?
Vector Markup Language (VML) is an application of XML 1.0 that defines the encoding of vector graphics in HTML. It was submitted to the W3C in 1998, but never gained traction. Instead, a working group at the W3C created Scalable Vector Graphics (SVG), which became a W3C Recommendation in 2001.
Techopedia explains Vector Markup Language (VML)
Though other companies were involved, VML was primarily a Microsoft initiative. At least, you saw Microsoft's contribution through its support starting with IE 5.0 and in Office 2000. While Microsoft has continued to support VML, pretty much every other web browser has supported SVG.