diff --git a/whats-new.md b/whats-new.md
index 101915eb..9c31d596 100644
--- a/whats-new.md
+++ b/whats-new.md
@@ -12,15 +12,11 @@ kleisauke and others for their great work on this release.
 [Lunaphore](https://www.lunaphore.ch/) kindly sponsored the development of
 the new JPEG2000 features, see below.
 
-# Loadable modules for some image format loaders
-
-- move openslide, libheif, poppler and magick to loadable modules [kleisauke]
-
 # Experimental JPEG-XL support
 
 libvips 8.11 includes experimental support for JPEG-XL load and save.
 
-(JPEG-XL)[https://jpeg.org/jpegxl/] is a promising new iteration of the JPEG
+[JPEG-XL](https://jpeg.org/jpegxl/) is a promising new iteration of the JPEG
 standard that's currently being developed. The Chrome web browser supports
 it, though behind a flag, and it looks like it might be enabled by default
 this autumn in Chrome 89. 
@@ -64,8 +60,32 @@ be squeezed out.
 
 # Thread recycling
 
-- new threading model has a single threadpool shared by all 
-  pipelines [kleisauke]
+The threading system of libvips was revamped, the new implementation uses
+the [thread pool semantics of GLib](https://developer.gnome.org/glib/stable/glib-Thread-Pools.html),
+which is a single thread pool shared across all pipelines. This
+implementation allows the reuse of already started threads.
+
+This was originally intended for WebAssembly but it turned out to be useful
+for native environments as well. Relative speed-ups are varying between ~4%
+and ~15% compared to the previous implementation. Especially for short-lived
+pipelines and long-running processes, a performance improvement can be observed.
+
+# Loadable modules for some dependencies
+
+libvips now supports building OpenSlide, libheif, Poppler and libMagick as a
+dynamically loadable module. This makes it easier for distributions to provide
+separate (optional) packages for these dependencies, making the core package
+much slimmer and thus reducing the attack surface. Distributing separate packages
+could also help to comply with GPL licensing (“mere aggregation” clause) or
+patent-encumbered software.
+
+[GModule](https://developer.gnome.org/glib/stable/glib-Dynamic-Loading-of-Modules.html)
+is used to accomplish this in a portable way. We already had a simple plugin
+system based on this, but the build part was not yet implemented.
+
+These loadable modules are built automatically when GModule is supported, which
+should be supported on at least Linux, Windows and macOS. It can be disabled
+by passing `--disable-modules` while configuring libvips.
 
 # Full-colour text rendering