7 files changed, 13 insertions, 12 deletions
diff --git a/doc/changelog.doc b/doc/changelog.doc
index 3ba6787..ca00728 100644
--- a/doc/changelog.doc
+++ b/doc/changelog.doc
@@ -2182,7 +2182,7 @@ make sure you add the following:
 <h3>New features</h3>
 <ul>
 <li>   Added support for 
-       <a href="http://daringfireball.net/projects/markdown/">Markdown</a>
+       <a href="https://daringfireball.net/projects/markdown/">Markdown</a>
        formatting.
        This is enabled by default, but can be disabled by 
        setting MARKDOWN_SUPPORT to NO. When enabled the following is 
diff --git a/doc/docblocks.doc b/doc/docblocks.doc
index f02e55b..ab144af 100644
--- a/doc/docblocks.doc
+++ b/doc/docblocks.doc
@@ -632,7 +632,7 @@ and is ideal for a short description.
 For longer descriptions you often will find the 
 need for some more structure, like a block of verbatim text, a list, or a 
 simple table. For this doxygen supports the 
-<a href="http://daringfireball.net/projects/markdown/syntax">Markdown</a> 
+<a href="https://daringfireball.net/projects/markdown/syntax">Markdown</a> 
 syntax, including parts of the
 <a href="https://michelf.ca/projects/php-markdown/extra/">Markdown Extra</a>
 extension. 
@@ -648,8 +648,9 @@ forms of additional markup on top of Markdown formatting.
 
 1. <a href="https://en.wikipedia.org/wiki/Javadoc">Javadoc</a> like markup.
    See \ref commands for a complete overview of all commands supported by doxygen.
-2. <a href="https://en.wikipedia.org/wiki/C_Sharp_(programming_language)#XML_documentation_system">XML</a> markup
-   as specified in the C# standard. See \ref xmlcmds for the XML commands supported by doxygen.
+2. <a href="https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/xmldoc/recommended-tags-for-documentation-comments">XML</a> markup
+   as specified in the <a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/c042926_ISO_IEC_23270_2006(E).zip">C# standard</a>.
+   See \ref xmlcmds for the XML commands supported by doxygen.
 
 If this is still not enough doxygen also supports a \ref htmlcmds "subset" of 
 the <a href="https://en.wikipedia.org/wiki/HTML">HTML</a> markup language.
diff --git a/doc/features.doc b/doc/features.doc
index f6aa7c1..fbbdf44 100644
--- a/doc/features.doc
+++ b/doc/features.doc
@@ -100,7 +100,7 @@
 Although doxygen can now be used in any project written in a language that is 
 supported by doxygen, initially it was specifically designed to be used for projects 
 that make use of Qt Software's 
-<A HREF="http://qt-project.org/">Qt toolkit</A>. I have tried to 
+<A HREF="https://www.qt.io/developers/">Qt toolkit</A>. I have tried to 
 make doxygen `Qt-compatible'. That is: Doxygen can read the documentation contained in 
 the Qt source code and create a class browser that looks quite similar to the 
 one that is generated by Qt Software. Doxygen understands the C++ extensions 
diff --git a/doc/install.doc b/doc/install.doc
index 7df0dee..d64b259 100644
--- a/doc/install.doc
+++ b/doc/install.doc
@@ -47,7 +47,7 @@ tools should be installed.
 
 <ul>
 <li>Qt Software's GUI toolkit 
-    <a href="http://qt-project.org/">Qt</A>
+    <a href="https://www.qt.io/developers/">Qt</A>
     \addindex Qt
     version 4.3 or higher (including Qt 5).
     This is needed to build the GUI front-end doxywizard. 
@@ -211,12 +211,12 @@ If you want to produce compressed HTML files (see \ref
 cfg_generate_htmlhelp "GENERATE_HTMLHELP") in the configuration file, then 
 you need the Microsoft HTML help workshop. 
 You can download it from 
-<a href="http://www.microsoft.com/en-us/download/details.aspx?id=21138">Microsoft</a>.
+<a href="https://www.microsoft.com/en-us/download/details.aspx?id=21138">Microsoft</a>.
 
 If you want to produce Qt Compressed Help files (see \ref 
 cfg_qhg_location "QHG_LOCATION") in the configuration file, then 
 you need qhelpgenerator which is part of Qt. 
-You can download Qt from <a href="http://qt-project.org/downloads">Qt Software Downloads</a>.
+You can download Qt from <a href="https://www.qt.io/download">Qt Software Downloads</a>.
 
 In order to generate PDF output or use scientific formulas you will also need to
 install <a href="https://en.wikipedia.org/wiki/LaTeX">LaTeX</a> and 
diff --git a/doc/markdown.doc b/doc/markdown.doc
index eebcb40..5edbaf9 100644
--- a/doc/markdown.doc
+++ b/doc/markdown.doc
@@ -41,7 +41,7 @@ the extensions that doxygen supports.
 Finally section \ref markdown_dox discusses some specifics for doxygen's
 implementation of the Markdown standard.
 
-[markdown]: http://daringfireball.net/projects/markdown/ 
+[markdown]: https://daringfireball.net/projects/markdown/ 
 [mdextra]:  https://michelf.ca/projects/php-markdown/extra/
 [github]:   https://github.github.com/github-flavored-markdown/
 
diff --git a/doc/searching.doc b/doc/searching.doc
index cb6b84a..9bc518a 100644
--- a/doc/searching.doc
+++ b/doc/searching.doc
@@ -126,7 +126,7 @@ has its own advantages and disadvantages:
    options you may want to set. After doxygen has finished you will find
    a Makefile in the HTML output directory. Running "make install" on this
    Makefile will compile and install the doc set.
-   See <a href="https://developer.apple.com/library/mac/#featuredarticles/DoxygenXcode/_index.html">this 
+   See <a href="https://developer.apple.com/library/archive/featuredarticles/DoxygenXcode/_index.html">this 
    article</a> for more info.
 
    Advantage of this method is that it nicely integrates with the Xcode
@@ -139,7 +139,7 @@ has its own advantages and disadvantages:
 <h2>6. Qt Compressed Help</h2> 
    If you develop for or want to install the Qt application framework,
    you will get an application 
-   called <a href="http://qt-project.org/doc/qt-4.8/assistant-manual.html">Qt assistant</a>. 
+   called <a href="http://doc.qt.io/archives/qt-4.8/assistant-manual.html">Qt assistant</a>. 
    This is a help viewer for Qt Compressed Help files (<code>.qch</code>).
 
    To enable this feature set \ref cfg_generate_qhp "GENERATE_QHP" to \c YES.
diff --git a/doc/starting.doc b/doc/starting.doc
index 0765a3b..64d3be0 100644
--- a/doc/starting.doc
+++ b/doc/starting.doc
@@ -263,7 +263,7 @@ capabilities of the man page format, so some information
 \subsection docbook_out DocBook output
 \addindex docbook
 Doxygen can also generate output in the 
-<a href="http://docbook.org/">DocBook</a> format. How to process the
+<a href="https://docbook.org/">DocBook</a> format. How to process the
 DocBook output is beyond the scope of this manual.
 
 \section step3 Step 3: Documenting the sources