- Post-first-browser-war version of spec: https://web.archive.org/web/20040407162455/http://www.bitstr...

- Natively supported in Netscape 4: https://web.archive.org/web/19970630083015fw_/http://develop...

- And was available as an ActiveX Control for IE4: https://web.archive.org/web/19990421092859/http://www.truedo... https://web.archive.org/web/19990224045109/http://www.truedo...

And despite being forgotten on Web still found a niche in various broadcast TV standards:

“The PFR specification defines the Bitstream portable font resource (PFR), which is a compact, platform-independent format for representing high-quality, scalable outline fonts. Many independent organizations responsible for setting digital TV standards have adopted the PFR font format as their standard font format, including:

- ATSC (Advanced Television Systems Committee)

- DAVIC (Digital Audio Visual Council)

- DVB (Digital Video Broadcasting)

- DTG (Digital TV Group)

- MHP (Multimedia Home Platform)

- ISO/IEC 16500-6:1999

- OCAP (OpenCable Application Platform)”

e: The linked 2022 retrospective does mention it in passing, but considering it shipped natively-supported in the #1 browser of the era I think it deserves to not be buried :) https://www.w3.org/TR/2022/NOTE-font-rationale-20220414/