etc/components;
isabelle makeall operates on all components with IsaMakefile;

--- a/NEWS	Tue Aug 04 16:11:11 2009 +0200
+++ b/NEWS	Tue Aug 04 16:13:16 2009 +0200
@@ -175,6 +175,12 @@
 
 *** System ***
 
+* Support for additional "Isabelle components" via etc/components, see
+also the system manual.
+
+* The isabelle makeall tool now operates on all components with
+IsaMakefile, not just hardwired "logics".
+
 * Discontinued support for Poly/ML 4.x versions.
 
 * Removed "compress" option from isabelle-process and isabelle usedir;