diff --git a/README.md b/README.md
index 6e97ea675..69ff495c6 100644
--- a/README.md
+++ b/README.md
@@ -480,21 +480,8 @@ how to build and install OSL.
 Documentation
 -------------
 
-The OSL language specification can be found at
-[src/doc/osl-languagespec.pdf](src/doc/osl-languagespec.pdf) (in a source
-distribution) or in the share/doc/OSL/osl-languagespec.pdf file of an
-installed binary distribution.
-
-[OSL Documentation on ReadTheDocs](https://docs.openshadinglanguage.org)
-This will be the future documentation. It's probably as complete as the PDF,
-but it needs some proofreading, so the PDF is still considered the
-authoritative source for now. But some time soon, the old PDF specification
-will be deprecated in favor of
-this online documentation.
-<!-- is the best place to start if you are interested in how to use OSL,
-its APIs. -->
-There is also a [PDF
-version](https://readthedocs.org/projects/open-shading-language/downloads/pdf/latest/).
+The OSL language specification can be found at [OSL Documentation on ReadTheDocs](https://docs.openshadinglanguage.org)
+There is also a [PDF version](https://readthedocs.org/projects/open-shading-language/downloads/pdf/stable/).
 
 For those interested in learning to program OSL shaders there is the
 [Siggraph 2024 Course](https://dl.acm.org/doi/proceedings/10.1145/3664475), 
@@ -559,16 +546,14 @@ Contacts, Links, and References
 
 [OSL GitHub page](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage)
 
-[Read or subscribe to the OSL development mail list](https://lists.aswf.io/g/osl-dev)
+[OSL Documentation on ReadTheDocs](https://docs.openshadinglanguage.org)
 
-[Most recent PDF of the OSL language specification](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/blob/main/src/doc/osl-languagespec.pdf
-)
+[Read or subscribe to the OSL development mail list](https://lists.aswf.io/g/osl-dev)
 
 [OSL home page](http://openshadinglanguage.org)
 
 
 
-
 Credits
 -------
 
diff --git a/src/doc/Makefile b/src/doc/Makefile
index 02c453d40..80b24303e 100644
--- a/src/doc/Makefile
+++ b/src/doc/Makefile
@@ -2,31 +2,12 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
 
-PDFLATEX_FLAGS = -interaction=errorstopmode   ###  "--shell-escape"
 
+# by default, make the sphinx documentation
+all: doxygen sphinx
 
-# by default, just make the document
-all: languagespec.pdf
 
-
-# document making rule: use pdflatex
-languagespec.pdf: *.tex Figures/*.pdf Figures/*png
-	pdflatex ${PDFLATEX_FLAGS} languagespec.tex
-
-
-
-# special command 'make index' to regenerate the index
-index: languagespec_index
-
-languagespec_index:
-	pdflatex ${PDFLATEX_FLAGS} languagespec.tex
-	makeindex languagespec
-	pdflatex ${PDFLATEX_FLAGS} languagespec.tex languagespec.aux macros.aux
-	pdflatex ${PDFLATEX_FLAGS} languagespec.tex languagespec.aux macros.aux languagespec.toc
-
-clean:
-	rm -f languagespec.aux languagespec.idx languagespec.ilg languagespec.ind languagespec.log
-	rm -f languagespec.out languagespec.pdf languagespec.toc macros.aux
+clean: doxygenclean
 
 .PHONY: clean