diff --git a/rhombus-lib/rhombus/private/amalgam/core-derived.rkt b/rhombus-lib/rhombus/private/amalgam/core-derived.rkt
index aac1421ee..572f755a9 100644
--- a/rhombus-lib/rhombus/private/amalgam/core-derived.rkt
+++ b/rhombus-lib/rhombus/private/amalgam/core-derived.rkt
@@ -6,6 +6,7 @@
         "check.rhm"
         "maybe.rhm"
         "string.rhm"
+        "path-object.rhm"
         "when_unless.rhm"
         "where.rhm"
         "described_as.rhm"
diff --git a/rhombus-lib/rhombus/private/amalgam/path-object.rhm b/rhombus-lib/rhombus/private/amalgam/path-object.rhm
new file mode 100644
index 000000000..b503caa08
--- /dev/null
+++ b/rhombus-lib/rhombus/private/amalgam/path-object.rhm
@@ -0,0 +1,33 @@
+#lang rhombus/private/amalgam/core
+
+import:
+  "core-meta.rkt" open
+
+use_static
+
+export:
+  PathString
+
+namespace PathString:
+  export:
+    to_path
+    to_complete_path
+
+  fun to_path(p :: PathString) :~ Path:
+    Path(p)
+
+  fun
+  | to_complete_path(p :: PathString):
+      Path.to_complete_path(p)
+  | to_complete_path(p :: PathString, ~relative_to: base_path :: PathString):
+      Path.to_complete_path(p, ~relative_to: base_path)
+
+  annot.macro 'to_path':
+    'converting(fun (p :: PathString) :~ Path: to_path(p))'
+
+  annot.macro
+  | 'to_complete_path(~relative_to: $base_path)':
+      'converting(fun (p :: PathString) :~ Path:
+                    to_complete_path(p, ~relative_to: $base_path))'
+  | 'to_complete_path':
+      'converting(fun (p :: PathString) :~ Path: to_complete_path(p))'
diff --git a/rhombus-lib/rhombus/private/amalgam/path-object.rkt b/rhombus-lib/rhombus/private/amalgam/path-object.rkt
index 6bd480552..ba4241336 100644
--- a/rhombus-lib/rhombus/private/amalgam/path-object.rkt
+++ b/rhombus-lib/rhombus/private/amalgam/path-object.rkt
@@ -5,15 +5,23 @@
          "realm.rkt"
          "call-result-key.rkt"
          "define-arity.rkt"
+         "append-key.rkt"
          "compare-key.rkt"
-         (submod "string.rkt" static-infos)
-         (submod "bytes.rkt" static-infos))
+         "index-result-key.rkt"
+         "static-info.rkt"
+         (submod "annotation.rkt" for-class)
+         (submod "bytes.rkt" static-infos)
+         (submod "function.rkt" for-info)
+         (submod "list.rkt" for-listable)
+         (submod "string.rkt" static-infos))
 
 (provide (for-spaces (rhombus/namespace
                       #f
                       rhombus/bind
                       rhombus/annot)
-                     Path))
+                     Path)
+         (for-space rhombus/annot
+                    PathString))
 
 (module+ for-builtin
   (provide path-method-table))
@@ -36,7 +44,8 @@
 (define-primitive-class Path path
   #:lift-declaration
   #:no-constructor-static-info
-  #:instance-static-info ((#%compare ((< path<?)
+  #:instance-static-info ((#%append Path.extend)
+                          (#%compare ((< path<?)
                                       (<= path<=?)
                                       (> path>?)
                                       (>= path>=?)
@@ -46,12 +55,19 @@
   #:translucent
   #:fields
   ([bytes Path.bytes #,(get-bytes-static-infos)])
+  #:namespace-fields
+  ([current_directory current-directory])
   #:properties
   ()
   #:methods
   (bytes
+   extend
+   is_absolute
+   parts
+   read_with
    string
-   ))
+   to_complete_path
+   write_with))
 
 (define/arity #:name Path (path c)
   #:static-infos ((#%call-result #,(get-path-static-infos)))
@@ -62,12 +78,46 @@
     [else (raise-argument-error* who rhombus-realm
                                  "String || Bytes || Path" c)]))
 
+(define-static-info-syntax current-directory
+  (#%function-arity 3)
+  (#%call-result #,(get-path-static-infos))
+  . #,(get-function-static-infos))
+
 (define/method (Path.bytes s)
   #:primitive (path->bytes)
   #:static-infos ((#%call-result #,(get-bytes-static-infos)))
   (bytes->immutable-bytes (path->bytes s)))
 
+(define/method (Path.extend p . ss)
+  #:primitive (build-path)
+  #:static-infos ((#%call-result #,(get-path-static-infos)))
+  (apply build-path p ss))
+
+(define/method (Path.is_absolute p)
+  #:primitive (absolute-path?)
+  (absolute-path? p))
+
+(define/method (Path.parts p)
+  #:primitive (explode-path)
+  #:static-infos ((#%call-result #,(get-treelist-static-infos)))
+  (to-treelist #f (explode-path p)))
+
+(define/method (Path.read_with p f)
+  #:primitive (call-with-input-file)
+  (call-with-input-file p f))
+
 (define/method (Path.string s)
   #:primitive (path->string)
   #:static-infos ((#%call-result #,(get-string-static-infos)))
   (string->immutable-string (path->string s)))
+
+(define/method (Path.to_complete_path p #:relative_to [base-path (current-directory)])
+  #:primitive (path->complete-path)
+  #:static-infos ((#%call-result #,(get-path-static-infos)))
+  (path->complete-path p base-path))
+
+(define/method (Path.write_with p f #:exists [exists 'error])
+  #:primitive (call-with-output-file)
+  (call-with-output-file p f #:exists exists))
+
+(define-annotation-syntax PathString (identifier-annotation path-string? ()))
diff --git a/rhombus-lib/rhombus/private/amalgam/port.rkt b/rhombus-lib/rhombus/private/amalgam/port.rkt
index 1f11ae05a..2c86e2046 100644
--- a/rhombus-lib/rhombus/private/amalgam/port.rkt
+++ b/rhombus-lib/rhombus/private/amalgam/port.rkt
@@ -71,7 +71,8 @@
    [open_bytes Port.Output.open_bytes]
    [open_string Port.Output.open_string]
    [get_bytes Port.Output.get_bytes]
-   [get_string Port.Output.get_string])
+   [get_string Port.Output.get_string]
+   ExistsFlag)
   #:properties ()
   #:methods
   ([flush Port.Output.flush]
@@ -124,6 +125,16 @@
   any
   [any_one any-one])
 
+(define-simple-symbol-enum ExistsFlag
+  error
+  replace
+  truncate
+  [must_truncate must-truncate]
+  [truncate_replace truncate/replace]
+  update
+  [can_update can-update]
+  append)
+
 (define (check-input-port who ip)
   (unless (input-port? ip)
     (raise-argument-error* who rhombus-realm "Port.Input" ip)))
@@ -139,6 +150,11 @@
     [(bstr) (open-input-bytes bstr)]
     [(bstr name) (open-input-bytes bstr name)]))
 
+(define/arity (Port.Input.open_file path)
+  #:primitive (open-input-file)
+  #:static-infos ((#%call-result #,(get-input-port-static-infos)))
+  (open-input-file path))
+
 (define/arity Port.Input.open_string
   #:primitive (open-input-string)
   #:static-infos ((#%call-result #,(get-input-port-static-infos)))
@@ -153,6 +169,11 @@
     [() (open-output-bytes)]
     [(name) (open-output-bytes name)]))
 
+(define/arity (Port.Output.open_file path #:exists [exists 'error])
+  #:primitive (open-output-file)
+  #:static-infos ((#%call-result #,(get-output-port-static-infos)))
+  (open-output-file path #:exists (->ExistsFlag exists)))
+
 (define/arity Port.Output.open_string
   #:primitive (open-output-string)
   #:static-infos ((#%call-result #,(get-output-string-port-static-infos)))
diff --git a/rhombus-lib/rhombus/private/amalgam/print.rkt b/rhombus-lib/rhombus/private/amalgam/print.rkt
index 0611255c3..4ff819dad 100644
--- a/rhombus-lib/rhombus/private/amalgam/print.rkt
+++ b/rhombus-lib/rhombus/private/amalgam/print.rkt
@@ -147,7 +147,10 @@
        [(display?)
         (display v op)]
        [else
-        (write v op)])]
+        (concat
+         (display "Path(" op)
+         (write (path->string v) op)
+         (display ")" op))])]
     [(and (procedure? v)
           (not (printer-ref v #f)))
      (define name (object-name v))
diff --git a/rhombus/rhombus/scribblings/reference/appendable.scrbl b/rhombus/rhombus/scribblings/reference/appendable.scrbl
index 91049d850..854866831 100644
--- a/rhombus/rhombus/scribblings/reference/appendable.scrbl
+++ b/rhombus/rhombus/scribblings/reference/appendable.scrbl
@@ -29,6 +29,7 @@ An @deftech{appendable} value is one that supports @rhombus(++). Maps,
   operator ((v1 :: ReadableString) ++ (v2 :: ReadableString))
     :: String
   operator ((v1 :: Bytes) ++ (v2 :: Bytes)) :: MutableBytes
+  operator ((v1 :: Path) ++ (v2 :: PathString)) :: Path
   operator ((v1 :: Appendable) ++ (v2 :: Appendable)) :: Any
 ){
 
diff --git a/rhombus/rhombus/scribblings/reference/path.scrbl b/rhombus/rhombus/scribblings/reference/path.scrbl
index 5c9a99179..2934248de 100644
--- a/rhombus/rhombus/scribblings/reference/path.scrbl
+++ b/rhombus/rhombus/scribblings/reference/path.scrbl
@@ -11,7 +11,12 @@ A @deftech{path} value represents a filesystem path.
   "path"
   Path
   path.bytes()
+  path.extend(part, ...)
+  path.is_absolute()
+  path.parts()
+  path.read_with(proc)
   path.string()
+  path.write_with(proc, ...)
 )
 
 Paths are @tech{comparable}, which means that generic operations like
@@ -19,13 +24,20 @@ Paths are @tech{comparable}, which means that generic operations like
 
 @doc(
   annot.macro 'Path'
+  annot.macro 'PathString'
+  annot.macro 'PathString.to_path'
 ){
 
- Matches a path value.
+ Matches a path value.  The @rhombus(PathString, ~annot) annotation allows
+ @rhombus(ReadableString, ~annot) as well as @rhombus(Path, ~annot) values.
+ The @rhombus(PathString.to_path, ~annot)
+ @tech(~doc: guide_doc){converter annotation} allows
+ @rhombus(PathString, ~annot) values, but converts
+ @rhombus(ReadableString, ~annot) values to @rhombus(Path) values.
 }
 
 @doc(
-  fun Path(path :: Bytes || String || Path) :: Path
+  fun Path(path :: Bytes || ReadableString || Path) :: Path
 ){
 
  Constructs a path given a byte string, string, or existing path. When a
@@ -69,6 +81,93 @@ Paths are @tech{comparable}, which means that generic operations like
 
 }
 
+@doc(
+  fun Path.extend(path :: Path,
+                  part :: PathString | #'up | #'same, ...) :: Path
+){
+
+  Creates a path given a base path and any number of sub-path
+  extensions. See also @rhombus(++).  If @rhombus(path) is an absolute path,
+  the result is an absolute path, otherwise the result is a relative path.
+
+  The @rhombus(path) and each @rhombus(part) must be either a relative
+  path, the symbol @rhombus(#'up) (indicating the relative parent
+  directory), or the symbol @rhombus(#'same) (indicating the
+  relative current directory).  For Windows paths, if @rhombus(path) is a
+  drive specification (with or without a trailing slash) the first
+  @rhombus(part) can be an absolute (driveless) path. For all platforms,
+  the last @rhombus(part) can be a filename.
+
+  The @rhombus(path) and @rhombus(part) arguments can be paths for
+  any platform. The platform for the resulting path is inferred from the
+  @rhombus(path) and @rhombus(part) arguments, where string arguments imply
+  a path for the current platform. If different arguments are for
+  different platforms, the @rhombus(Exn.Fail.Contract, ~class) exception
+  is thrown.  If no argument implies a platform (i.e., all are @rhombus(#'up)
+  or @rhombus(#'same)), the generated path is for the current platform.
+
+  Each @rhombus(part) and @rhombus(path) can optionally end in a directory
+  separator. If the last @rhombus(part) ends in a separator, it is
+  included in the resulting path.
+
+  The @rhombus(build-path) procedure builds a path @italic{without}
+  checking the validity of the path or accessing the filesystem.
+
+@examples(
+  def p = Path("/home/rhombus")
+  Path.extend(p, "shape.txt")
+  p.extend("shape.txt")
+  p ++ "shape.txt"
+)
+
+}
+
+@doc(fun Path.is_absolute(path :: Path)){
+
+ Returns @rhombus(#true) if @rhombus(path) is an absolute path, @rhombus(#false)
+ otherwise.  This procedure does not access the filesystem.
+}
+
+@doc(
+  fun Path.parts(path :: Path) :: List.of(Path || #'up || #'same)
+){
+
+  Returns a list of path elements that constitute @rhombus(path).
+
+  The @rhombus(Path.parts) function computes its result in time
+  proportional to the length of @rhombus(path).
+
+@examples(
+  def p = Path("/home/rhombus/shape.txt")
+  Path.parts(p)
+  p.parts()
+)
+
+}
+
+@doc(
+  fun Path.read_with(path :: Path, read_proc :: Function.of_arity(1))
+){
+
+ Opens @rhombus(path) for reading and calls @rhombus(read_proc) with the
+ @tech{input port}.  The result of @rhombus(read_proc) is the result of
+ @rhombus(Path.read_with).
+
+}
+
+@doc(
+  fun Path.write_with(path :: Path,
+                      proc :: Function.of_arity(1),
+                      ~exists: exists_flag
+                                 :: Port.Output.ExistsFlag = #'error)
+){
+
+ Opens @rhombus(path) for writing and calls @rhombus(write_proc) with the
+ @tech{output port}.  The result of @rhombus(write_proc) is the result of
+ @rhombus(Path.write_with).
+
+}
+
 @doc(
   fun Path.string(path :: Path) :: String
 ){
diff --git a/rhombus/rhombus/scribblings/reference/port.scrbl b/rhombus/rhombus/scribblings/reference/port.scrbl
index f38c387dc..5c53a5285 100644
--- a/rhombus/rhombus/scribblings/reference/port.scrbl
+++ b/rhombus/rhombus/scribblings/reference/port.scrbl
@@ -112,6 +112,14 @@ output. Moreover, an @deftech{input string port} or an
 
 }
 
+@doc(
+  fun Port.Input.open_file(file :: PathString) :: Port.Input
+){
+
+ Creates an @tech{input port} that reads from the @tech{path} @rhombus(file).
+
+}
+
 @doc(
   fun Port.Input.open_string(str :: ReadableString,
                              name :: Symbol = #'string)
@@ -314,6 +322,51 @@ output. Moreover, an @deftech{input string port} or an
 
 }
 
+@doc(
+  fun Port.Output.open_file(path :: PathString,
+                            ~exists: exists_flag
+                                       :: Port.Output.ExistsFlag = #'error)
+    :: Port.Output
+){
+
+ Creates an @tech{output port} that writes to the @tech{path} @rhombus(file).
+ The @rhombus(exists_flag) argument specifies how to handle/require
+ files that already exist:
+
+ @itemlist(
+
+  @item{@rhombus(#'error) --- throws @rhombus(Exn.Fail.Filesystem.Exists)
+        if the file exists.}
+
+  @item{@rhombus(#'replace) --- remove the old file, if it
+        exists, and write a new one.}
+
+  @item{@rhombus(#'truncate) --- remove all old data, if the file
+        exists.}
+
+  @item{@rhombus(#'must_truncate) --- remove all old data in an
+        existing file; if the file does not exist, the
+        @rhombus(Exn.Fail.Filesystem) exception is thrown.}
+
+  @item{@rhombus(#'truncate_replace) --- try @rhombus(#'truncate);
+        if it fails (perhaps due to file permissions), try
+        @rhombus(#'replace).}
+
+  @item{@rhombus(#'update) --- open an existing file without
+        truncating it; if the file does not exist, the
+        @rhombus(Exn.Fail.Filesystem) exception is thrown.}
+
+  @item{@rhombus(#'can_update) --- open an existing file without
+        truncating it, or create the file if it does not exist.}
+
+  @item{@rhombus(#'append) --- append to the end of the file,
+        whether it already exists or not; on Windows,
+        @rhombus(#'append) is equivalent to @rhombus(#'update), except that
+        the file is not required to exist, and the file position is
+        immediately set to the end of the file after opening it.}
+
+)}
+
 @doc(
   fun Port.Output.open_bytes(name :: Symbol = #'string)
     :: Port.Output.String
@@ -357,3 +410,19 @@ output. Moreover, an @deftech{input string port} or an
  Flushes the content of @rhombus(out)'s buffer.
 
 }
+
+@doc(
+  enum Port.Output.ExistsFlag:
+    error
+    append
+    update
+    can_update
+    replace
+    truncate
+    must_truncate
+    truncate_replace
+){
+
+  Flags for handling existing files when opening @tech{output ports}.
+
+}
diff --git a/rhombus/rhombus/tests/path.rhm b/rhombus/rhombus/tests/path.rhm
index 6cc40bce1..6fab86596 100644
--- a/rhombus/rhombus/tests/path.rhm
+++ b/rhombus/rhombus/tests/path.rhm
@@ -59,3 +59,35 @@ block:
     check p == q ~is #false
     check p != Path("/") ~is #false
     check p != q ~is #true
+
+block:
+  def s = "/etc"
+  def p1 = Path("/etc")
+  def p2 = (s :: PathString.to_path)
+  check p1 compares_equal p2 ~is #true
+  version_guard.at_least "8.13.0.1":
+    check p1 == p2 ~is #true
+
+block:
+  def p1 = Path("/etc/passwd")
+  check p1.parts() ~is [Path("/"), Path("etc"), Path("passwd")]
+  def p2 = Path("C:/windows")
+  check p2.parts() ~is [Path("C:"), Path("windows")]
+  def p3 = Path("../a/b/./c")
+  check p3.parts() ~is [#'up, Path("a"), Path("b"), #'same, Path("c")]
+
+block:
+  check Path("/").extend("etc", Path("passwd")) ~is Path("/etc/passwd")
+  check Path.extend("C:", "win32", "sys") ~is Path("C:/win32/sys")
+  check Path("/") ++ Path("etc") ++ "passwd" ~is Path("/etc/passwd")
+  check Path("..") ++ "a" ++ "b" ++ #'same ++ "c" ~is Path("../a/b/./c")
+
+block:
+  def p1 = Path("/etc")
+  def p2 = Path("etc")
+  check Path.is_absolute(p1) ~is #true
+  check Path.is_absolute("/etc") ~is #true
+  check p1.is_absolute() ~is #true
+  check Path.is_absolute(p2) ~is #false
+  check Path.is_absolute("etc") ~is #false
+  check p2.is_absolute() ~is #false