diff --git a/CHANGELOG.md b/CHANGELOG.md
index 29af2365..47b22886 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,7 @@ All notable changes to this project will be documented in this file.
 - Use `(doc)` with no arguments to see available bindings and dynamic bindings.
 - `jpm` will use `CC` and `AR` environment variables when compiling programs.
 - Add `comptime` macro for compile time evaluation.
+- Run `main` functions in scripts if they exist, just like jpm standalone binaries.
 - Numerous small bug fixes and usability improvements.
 
 ### 1.5.1 - 2019-11-16
diff --git a/src/boot/boot.janet b/src/boot/boot.janet
index a2255de4..c11bcac8 100644
--- a/src/boot/boot.janet
+++ b/src/boot/boot.janet
@@ -1866,7 +1866,6 @@
   [image]
   (unmarshal image (env-lookup _env)))
 
-(def- nati (if (= :windows (os/which)) ".dll" ".so"))
 (defn- check-. [x] (if (string/has-prefix? "." x) x))
 (defn- not-check-. [x] (unless (string/has-prefix? "." x) x))
 
@@ -1883,19 +1882,19 @@
     [":cur:/:all:.jimage" :image check-.]
     [":cur:/:all:.janet" :source check-.]
     [":cur:/:all:/init.janet" :source check-.]
-    [(string ":cur:/:all:" nati) :native check-.]
+    [":cur:/:all::native:" :native check-.]
 
     # As a path from (os/cwd)
     [":all:.jimage" :image not-check-.]
     [":all:.janet" :source not-check-.]
     [":all:/init.janet" :source not-check-.]
-    [(string ":all:" nati) :native not-check-.]
+    [":all::native:" :native not-check-.]
 
     # System paths
     [":sys:/:all:.jimage" :image not-check-.]
     [":sys:/:all:.janet" :source not-check-.]
     [":sys:/:all:/init.janet" :source not-check-.]
-    [(string ":sys:/:all:" nati) :native not-check-.]])
+    [":sys:/:all::native:" :native not-check-.]])
 
 (setdyn :syspath (boot/opts "JANET_PATH"))
 (setdyn :headerpath (boot/opts "JANET_HEADERPATH"))
@@ -1949,7 +1948,6 @@
       [nil (string "could not find module " path ":\n    " ;str-parts)])))
 
 (put _env 'fexists nil)
-(put _env 'nati nil)
 (put _env 'mod-filter nil)
 (put _env 'check-. nil)
 (put _env 'not-check-. nil)
diff --git a/src/core/corelib.c b/src/core/corelib.c
index afcb0bfc..7e2b3ced 100644
--- a/src/core/corelib.c
+++ b/src/core/corelib.c
@@ -177,6 +177,13 @@ static Janet janet_core_expand_path(int32_t argc, Janet *argv) {
             } else if (strncmp(template + i, ":name:", 6) == 0) {
                 janet_buffer_push_cstring(out, name);
                 i += 5;
+            } else if (strncmp(template + i, ":native:", 8) == 0) {
+#ifdef JANET_WINDOWS
+                janet_buffer_push_cstring(out, ".dll");
+#else
+                janet_buffer_push_cstring(out, ".so");
+#endif
+                i += 7;
             } else {
                 janet_buffer_push_u8(out, (uint8_t) template[i]);
             }
@@ -668,7 +675,13 @@ static const JanetReg corelib_cfuns[] = {
              "Expands a path template as found in module/paths for module/find. "
              "This takes in a path (the argument to require) and a template string, template, "
              "to expand the path to a path that can be "
-             "used for importing files.")
+             "used for importing files. The replacements are as follows:\n\n"
+             "\t:all:\tthe value of path verbatim\n"
+             "\t:cur:\tthe current file, or (dyn :current-file)\n"
+             "\t:dir:\tthe directory containing the current file\n"
+             "\t:name:\tthe filename component of path, with extenion if given\n"
+             "\t:native:\tthe extension used to load natives, .so or .dll\n"
+             "\t:sys:\tthe system path, or (syn :syspath)")
     },
     {
         "int?", janet_core_check_int,