The extension name seems to be usually totally lower-cased.

foobar · foobar · commit 2c95a1d690e4 · 2001-06-24T22:18:51.000Z
diff --git a/ext/calendar/calendar.c b/ext/calendar/calendar.c
@@ -48,7 +48,7 @@ function_entry calendar_functions[] = {
 
 
 zend_module_entry calendar_module_entry = {
-  "Calendar", 
+  "calendar", 
   calendar_functions, 
   NULL, /*PHP_MINIT(calendar),*/
   NULL,
diff --git a/ext/session/mod_mm.c b/ext/session/mod_mm.c
@@ -345,7 +345,7 @@ PS_GC_FUNC(mm)
 }
 
 zend_module_entry php_session_mm_module = {
-	"Session MM",
+	"session mm",
 	NULL,
 	PHP_MINIT(ps_mm), PHP_MSHUTDOWN(ps_mm),
 	NULL, NULL,
diff --git a/ext/yaz/php_yaz.c b/ext/yaz/php_yaz.c
@@ -2468,7 +2468,7 @@ PHP_RINIT_FUNCTION(yaz)
 }
 
 zend_module_entry yaz_module_entry = {
-	"YAZ",
+	"yaz",
 	yaz_functions,
 	PHP_MINIT(yaz),
 	PHP_MSHUTDOWN(yaz),

Original file line number	Diff line number	Diff line change
`@@ -345,7 +345,7 @@ PS_GC_FUNC(mm)`
`345`	`345`	`}`
`346`	`346`
`347`	`347`	`zend_module_entry php_session_mm_module = {`
`348`		`- "Session MM",`
	`348`	`+ "session mm",`
`349`	`349`	`NULL,`
`350`	`350`	`PHP_MINIT(ps_mm), PHP_MSHUTDOWN(ps_mm),`
`351`	`351`	`NULL, NULL,`
Original file line number	Diff line number	Diff line change
`@@ -2468,7 +2468,7 @@ PHP_RINIT_FUNCTION(yaz)`
`2468`	`2468`	`}`
`2469`	`2469`
`2470`	`2470`	`zend_module_entry yaz_module_entry = {`
`2471`		`- "YAZ",`
	`2471`	`+ "yaz",`
`2472`	`2472`	`yaz_functions,`
`2473`	`2473`	`PHP_MINIT(yaz),`
`2474`	`2474`	`PHP_MSHUTDOWN(yaz),`