diff --git a/CHANGELOG.md b/CHANGELOG.md
index 22355ab8..87f5dcbe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,28 @@
 # Changelog
 
+## 0.8
+
+- add `@Emm` to authors
+- refactored heavily `CCFuture` (much simpler, cleaner, basic API and thread pool)
+- add `CCLock` in containers.thread
+- merged `test_levenshtein` with other tests
+- Add experimental rose tree in `Containers_misc.RoseTree`.
+- remove a lot of stuff from `containers.misc` (see `_oasis` for details)
+- `make devel` command, activating most flags, for developpers (see #27)
+- use benchmark 1.4, with the upstreamed tree system
+- test `ccvector.iteri`
+- add `CCFormat` into core/
+- infix map operators for `CCArray`
+- `fold_while` impl for `CCList` and `CCArray`
+- Added `CCBigstring.length` for more consistency with the `CCString` module.
+- Added name and dev fields in the OPAM file for local pinning.
+- Fix `CCIO.remove*` functions.
+- Added `CCIO.remove_safe`.
+- only build doc if all the required flags are enabled
+- `CCHashtbl.{keys,values}_list` in the functor as well. Better doc.
+- `CCHashtbl.{keys,values}_list`
+- more accurate type for `CCHashtbl.Make`
+
 ## 0.7
 
 ### breaking
diff --git a/README.md b/README.md
index 21d7cd5c..bb8bcd40 100644
--- a/README.md
+++ b/README.md
@@ -147,6 +147,7 @@ is not necessarily up-to-date.
 - `AbsSet`, an abstract Set data structure, a bit like `LazyGraph`.
 - `Automaton`, `CSM`, state machine abstractions
 - `Bij`, a GADT-based bijection language used to serialize/deserialize your data structures
+- `Hashset`, a polymorphic imperative set on top of `PHashtbl`
 - `LazyGraph`, a lazy graph structure on arbitrary (hashable+eq) types, with basic graph functions that work even on infinite graphs, and printing to DOT.
 - `PHashtbl`, a polymorphic hashtable (with open addressing)
 - `RAL`, a random-access list structure, with `O(1)` cons/hd/tl and `O(ln(n))` access to elements by their index.
diff --git a/_oasis b/_oasis
index 112908ed..b348e689 100644
--- a/_oasis
+++ b/_oasis
@@ -1,6 +1,6 @@
 OASISFormat: 0.4
 Name:        containers
-Version:     0.7
+Version:     0.8
 Homepage:    https://github.com/c-cube/ocaml-containers
 Authors:     Simon Cruanes
 License:     BSD-2-clause
@@ -113,7 +113,7 @@ Library "containers_pervasives"
 Library "containers_misc"
   Path:             src/misc
   Pack:             true
-  Modules:          AbsSet, Automaton, Bij, CSM, LazyGraph, PHashtbl,
+  Modules:          AbsSet, Automaton, Bij, CSM, Hashset, LazyGraph, PHashtbl,
                     PrintBox, RAL, RoseTree, SmallSet, UnionFind, Univ
   BuildDepends:     containers, containers.data
   FindlibName:      misc
diff --git a/doc/intro.txt b/doc/intro.txt
index ff7c5e99..edbad184 100644
--- a/doc/intro.txt
+++ b/doc/intro.txt
@@ -118,6 +118,7 @@ AbsSet
 Automaton
 Bij
 CSM
+Hashset
 LazyGraph
 PHashtbl
 PrintBox
diff --git a/src/bigarray/CCBigstring.mli b/src/bigarray/CCBigstring.mli
index 33970486..dbd6ebc9 100644
--- a/src/bigarray/CCBigstring.mli
+++ b/src/bigarray/CCBigstring.mli
@@ -47,7 +47,7 @@ val size : t -> int
 
 val length : t -> int
 (** Alias for [size].
-    @since NEXT_RELEASE *)
+    @since 0.8 *)
 
 val get : t -> int -> char
 
diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index e4e10882..faeb7a4c 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -56,7 +56,7 @@ module type S = sig
   val fold_while : ('a -> 'b -> 'a * [`Stop | `Continue]) -> 'a -> 'b t -> 'a
   (** fold left on array until a stop condition via [('a, `Stop)] is
       indicated by the accumulator
-      @since NEXT_RELEASE *)
+      @since 0.8 *)
 
   val iter : ('a -> unit) -> 'a t -> unit
 
diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index 1a5c26a4..403578e6 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -58,7 +58,7 @@ module type S = sig
   val fold_while : ('a -> 'b -> 'a * [`Stop | `Continue]) -> 'a -> 'b t -> 'a
   (** Fold left on array until a stop condition via [('a, `Stop)] is
       indicated by the accumulator
-      @since NEXT_RELEASE *)
+      @since 0.8 *)
 
   val iter : ('a -> unit) -> 'a t -> unit
 
@@ -157,11 +157,11 @@ val (>>=) : 'a t -> ('a -> 'b t) -> 'b t
 
 val (>>|) : 'a t -> ('a -> 'b) -> 'b t
 (** Infix version of {!map}
-    @since NEXT_RELEASE *)
+    @since 0.8 *)
 
 val (>|=) : 'a t -> ('a -> 'b) -> 'b t
 (** Infix version of {!map}
-    @since NEXT_RELEASE *)
+    @since 0.8 *)
 
 val except_idx : 'a t -> int -> 'a list
 (** Remove given index, obtaining the list of the other elements *)
diff --git a/src/core/CCFormat.mli b/src/core/CCFormat.mli
index d8c06657..6a4c46f6 100644
--- a/src/core/CCFormat.mli
+++ b/src/core/CCFormat.mli
@@ -26,7 +26,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 (** {1 Helpers for Format}
 
-@since NEXT_RELEASE *)
+@since 0.8 *)
 
 type 'a sequence = ('a -> unit) -> unit
 
diff --git a/src/core/CCHashtbl.ml b/src/core/CCHashtbl.ml
index 580e6f29..19ade6b6 100644
--- a/src/core/CCHashtbl.ml
+++ b/src/core/CCHashtbl.ml
@@ -86,11 +86,11 @@ module type S = sig
 
   val keys_list : ('a, 'b) Hashtbl.t -> 'a list
   (** [keys t] is the list of keys in [t].
-      @since NEXT_RELEASE *)
+      @since 0.8 *)
 
   val values_list : ('a, 'b) Hashtbl.t -> 'b list
   (** [values t] is the list of values in [t].
-      @since NEXT_RELEASE *)
+      @since 0.8 *)
 
   val map_list : (key -> 'a -> 'b) -> 'a t -> 'b list
   (** Map on a hashtable's items, collect into a list *)
diff --git a/src/core/CCHashtbl.mli b/src/core/CCHashtbl.mli
index b862bcad..554196ca 100644
--- a/src/core/CCHashtbl.mli
+++ b/src/core/CCHashtbl.mli
@@ -46,11 +46,11 @@ val values : ('a,'b) Hashtbl.t -> 'b sequence
 
 val keys_list : ('a, 'b) Hashtbl.t -> 'a list
 (** [keys t] is the list of keys in [t].
-    @since NEXT_RELEASE *)
+    @since 0.8 *)
 
 val values_list : ('a, 'b) Hashtbl.t -> 'b list
 (** [values t] is the list of values in [t].
-    @since NEXT_RELEASE *)
+    @since 0.8 *)
 
 val map_list : ('a -> 'b -> 'c) -> ('a, 'b) Hashtbl.t -> 'c list
 (** Map on a hashtable's items, collect into a list *)
@@ -83,11 +83,11 @@ module type S = sig
 
   val keys_list : ('a, 'b) Hashtbl.t -> 'a list
   (** [keys t] is the list of keys in [t].
-      @since NEXT_RELEASE *)
+      @since 0.8 *)
 
   val values_list : ('a, 'b) Hashtbl.t -> 'b list
   (** [values t] is the list of values in [t].
-      @since NEXT_RELEASE *)
+      @since 0.8 *)
 
   val map_list : (key -> 'a -> 'b) -> 'a t -> 'b list
   (** Map on a hashtable's items, collect into a list *)
diff --git a/src/core/CCList.mli b/src/core/CCList.mli
index 8400351a..57a2944d 100644
--- a/src/core/CCList.mli
+++ b/src/core/CCList.mli
@@ -51,7 +51,7 @@ val fold_right : ('a -> 'b -> 'b) -> 'a t -> 'b -> 'b
 val fold_while : ('a -> 'b -> 'a * [`Stop | `Continue]) -> 'a -> 'b t -> 'a
 (** Fold until a stop condition via [('a, `Stop)] is
     indicated by the accumulator
-    @since NEXT_RELEASE *)
+    @since 0.8 *)
 
 val init : int -> (int -> 'a) -> 'a t
 (** Same as [Array.init]
diff --git a/src/io/CCIO.mli b/src/io/CCIO.mli
index a7e43112..e338ef16 100644
--- a/src/io/CCIO.mli
+++ b/src/io/CCIO.mli
@@ -152,15 +152,15 @@ module File : sig
       file system.
 
       {b Raises} [Sys_error] if there is no file at [path].
-      @since NEXT_RELEASE *)
+      @since 0.8 *)
 
   val remove : t -> unit or_error
   (** Like [remove_exn] but with an error monad.
-      @since NEXT_RELEASE *)
+      @since 0.8 *)
 
   val remove_noerr : t -> unit
   (** Like [remove_exn] but do not raise any exception on failure.
-      @since NEXT_RELEASE *)
+      @since 0.8 *)
 
   val read_dir : ?recurse:bool -> t -> t gen
   (** [read_dir d] returns a sequence of files and directory contained
diff --git a/src/misc/hashset.ml b/src/misc/hashset.ml
new file mode 100644
index 00000000..110e4994
--- /dev/null
+++ b/src/misc/hashset.ml
@@ -0,0 +1,75 @@
+(*
+Copyright (c) 2013, Simon Cruanes
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.  Redistributions in binary
+form must reproduce the above copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other materials provided with
+the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*)
+
+(** {1 Mutable polymorphic hash-set} *)
+
+type 'a sequence = ('a -> unit) -> unit
+
+type 'a t = ('a, unit) PHashtbl.t
+  (** A set is a hashtable, with trivial values *)
+
+let empty ?max_load ?eq ?hash size =
+  PHashtbl.create ?max_load ?eq ?hash size
+
+let copy set = PHashtbl.copy set
+
+let clear set = PHashtbl.clear set
+
+let cardinal set = PHashtbl.length set
+
+let mem set x = PHashtbl.mem set x
+
+let add set x = PHashtbl.add set x ()
+
+let remove set x = PHashtbl.remove set x
+
+let iter f set = PHashtbl.iter (fun x () -> f x) set
+
+let fold f acc set = PHashtbl.fold (fun acc x () -> f acc x) acc set
+
+let filter p set = PHashtbl.filter (fun x () -> p x) set 
+
+let to_seq set k = iter k set
+
+let of_seq set seq =
+  seq (fun x -> add set x)
+
+let union ?into (s1 : 'a t) (s2 : 'a t) =
+  let into = match into with
+  | Some s -> of_seq s (to_seq s1); s
+  | None -> copy s1 in
+  of_seq into (to_seq s2);
+  into
+
+let seq_filter p seq k =
+  seq (fun x -> if p x then k x)
+
+let inter ?into (s1 : 'a t) (s2 : 'a t) =
+  let into = match into with
+  | Some s -> s
+  | None -> empty ~eq:s1.PHashtbl.eq ~hash:s1.PHashtbl.hash (cardinal s1) in
+  (* add to [into] elements of [s1] that also belong to [s2] *)
+  of_seq into (seq_filter (fun x -> mem s2 x) (to_seq s1));
+  into
diff --git a/src/misc/hashset.mli b/src/misc/hashset.mli
new file mode 100644
index 00000000..f421c557
--- /dev/null
+++ b/src/misc/hashset.mli
@@ -0,0 +1,64 @@
+(*
+Copyright (c) 2013, Simon Cruanes
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.  Redistributions in binary
+form must reproduce the above copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other materials provided with
+the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*)
+
+(** {1 Mutable polymorphic hash-set} *)
+
+type 'a sequence = ('a -> unit) -> unit
+
+type 'a t = ('a, unit) PHashtbl.t
+  (** A set is a hashtable, with trivial values *)
+
+val empty : ?max_load:float -> ?eq:('a -> 'a -> bool) ->
+            ?hash:('a -> int) -> int -> 'a t
+  (** See {!PHashtbl.create} *)
+
+val copy : 'a t -> 'a t
+
+val clear : 'a t -> unit
+
+val cardinal : 'a t -> int
+
+val mem : 'a t -> 'a -> bool
+
+val add : 'a t -> 'a -> unit
+
+val remove : 'a t -> 'a -> unit
+
+val iter : ('a -> unit) -> 'a t -> unit
+
+val fold : ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b
+
+val filter : ('a -> bool) -> 'a t -> unit
+  (** destructive filter (remove elements that do not satisfy the predicate) *)
+
+val to_seq : 'a t -> 'a sequence
+
+val of_seq : 'a t -> 'a sequence -> unit
+
+val union : ?into:'a t -> 'a t -> 'a t -> 'a t
+  (** Set union. The result is stored in [into] *)
+
+val inter : ?into:'a t -> 'a t -> 'a t -> 'a t
+  (** Set intersection. The result is stored in [into] *)
diff --git a/src/misc/roseTree.mli b/src/misc/roseTree.mli
index 00773464..cbaf42bb 100644
--- a/src/misc/roseTree.mli
+++ b/src/misc/roseTree.mli
@@ -29,7 +29,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    A persistent, non-lazy tree where each node may have an arbitrary number of
    children.
 
-   @since NEXT_RELEASE *)
+   @since 0.8 *)
 
 (** The type of a tree node - a (value, children) pair.  *)
 type +'a t = [`Node of 'a * 'a t list]
diff --git a/src/threads/CCLock.mli b/src/threads/CCLock.mli
index 33840712..cfb05eb4 100644
--- a/src/threads/CCLock.mli
+++ b/src/threads/CCLock.mli
@@ -27,7 +27,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 (** {1 Utils around Mutex}
 
-@since NEXT_RELEASE *)
+@since 0.8 *)
 
 type 'a t
 (** A value surrounded with a lock *)