diff --git a/.github/actions/install/action.yml b/.github/actions/install/action.yml
index e9864c01..3b29b7b2 100644
--- a/.github/actions/install/action.yml
+++ b/.github/actions/install/action.yml
@@ -17,7 +17,7 @@ inputs:
   zig-v8:
     description: 'zig v8 version to install'
     required: false
-    default: 'v0.1.33'
+    default: 'v0.1.35'
   v8:
     description: 'v8 version to install'
     required: false
@@ -26,6 +26,10 @@ inputs:
     description: 'cache dir to use'
     required: false
     default: '~/.cache'
+  mode:
+    description: 'debug or release'
+    required: false
+    default: 'debug'
 
 runs:
   using: "composite"
@@ -38,7 +42,7 @@ runs:
         sudo apt-get update
         sudo apt-get install -y wget xz-utils python3 ca-certificates git pkg-config libglib2.0-dev gperf libexpat1-dev cmake clang
 
-    - uses: mlugg/setup-zig@v2
+    - uses: mlugg/setup-zig@v2.0.5
       with:
         version: ${{ inputs.zig }}
 
@@ -58,37 +62,26 @@ runs:
 
         wget -O ${{ inputs.cache-dir }}/v8/libc_v8.a https://github.com/lightpanda-io/zig-v8-fork/releases/download/${{ inputs.zig-v8 }}/libc_v8_${{ inputs.v8 }}_${{ inputs.os }}_${{ inputs.arch }}.a
 
-    - name: install v8
+    - name: install v8 release
+      if: ${{ inputs.mode == 'release' }}
+      shell: bash
+      run: |
+        mkdir -p v8/out/${{ inputs.os }}/release/obj/zig/
+        ln -s ${{ inputs.cache-dir }}/v8/libc_v8.a v8/out/${{ inputs.os }}/release/obj/zig/libc_v8.a
+
+    - name: install v8 debug
+      if: ${{ inputs.mode == 'debug' }}
       shell: bash
       run: |
         mkdir -p v8/out/${{ inputs.os }}/debug/obj/zig/
         ln -s ${{ inputs.cache-dir }}/v8/libc_v8.a v8/out/${{ inputs.os }}/debug/obj/zig/libc_v8.a
 
-        mkdir -p v8/out/${{ inputs.os }}/release/obj/zig/
-        ln -s ${{ inputs.cache-dir }}/v8/libc_v8.a v8/out/${{ inputs.os }}/release/obj/zig/libc_v8.a
-
-    - name: Cache libiconv
-      id: cache-libiconv
-      uses: actions/cache@v4
-      env:
-        cache-name: cache-libiconv
-      with:
-        path: ${{ inputs.cache-dir }}/libiconv
-        key: vendor/libiconv/libiconv-1.17
-
-    - name: download libiconv
-      if: ${{ steps.cache-libiconv.outputs.cache-hit != 'true' }}
+    - name: hmtl5ever release
+      if: ${{ inputs.mode == 'release' }}
       shell: bash
-      run: make download-libiconv
+      run: zig build -Doptimize=ReleaseFast html5ever
 
-    - name: build libiconv
+    - name: hmtl5ever debug
+      if: ${{ inputs.mode == 'debug' }}
       shell: bash
-      run: make build-libiconv
-
-    - name: build mimalloc
-      shell: bash
-      run: make install-mimalloc
-
-    - name: build netsurf
-      shell: bash
-      run: make install-netsurf
+      run: zig build html5ever
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index df16af4c..0ab034e8 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -36,6 +36,7 @@ jobs:
         with:
           os: ${{env.OS}}
           arch: ${{env.ARCH}}
+          mode: 'release'
 
       - name: zig build
         run: zig build --release=safe -Doptimize=ReleaseSafe -Dcpu=x86_64 -Dgit_commit=$(git rev-parse --short ${{ github.sha }})
@@ -74,6 +75,7 @@ jobs:
         with:
           os: ${{env.OS}}
           arch: ${{env.ARCH}}
+          mode: 'release'
 
       - name: zig build
         run: zig build --release=safe -Doptimize=ReleaseSafe -Dcpu=generic -Dgit_commit=$(git rev-parse --short ${{ github.sha }})
@@ -114,6 +116,7 @@ jobs:
         with:
           os: ${{env.OS}}
           arch: ${{env.ARCH}}
+          mode: 'release'
 
       - name: zig build
         run: zig build --release=safe -Doptimize=ReleaseSafe -Dgit_commit=$(git rev-parse --short ${{ github.sha }})
@@ -157,6 +160,7 @@ jobs:
         with:
           os: ${{env.OS}}
           arch: ${{env.ARCH}}
+          mode: 'release'
 
       - name: zig build
         run: zig build --release=safe -Doptimize=ReleaseSafe -Dgit_commit=$(git rev-parse --short ${{ github.sha }})
diff --git a/.github/workflows/e2e-test.yml b/.github/workflows/e2e-test.yml
index fb295246..992c8b2a 100644
--- a/.github/workflows/e2e-test.yml
+++ b/.github/workflows/e2e-test.yml
@@ -56,6 +56,8 @@ jobs:
           submodules: recursive
 
       - uses: ./.github/actions/install
+        with:
+          mode: 'release'
 
       - name: zig build release
         run: zig build -Doptimize=ReleaseFast -Dcpu=x86_64 -Dgit_commit=$(git rev-parse --short ${{ github.sha }})
diff --git a/Dockerfile b/Dockerfile
index 919a9a65..a405a057 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,7 +4,7 @@ ARG MINISIG=0.12
 ARG ZIG=0.15.2
 ARG ZIG_MINISIG=RWSGOq2NVecA2UPNdBUZykf1CCb147pkmdtYxgb3Ti+JO/wCYvhbAb/U
 ARG V8=14.0.365.4
-ARG ZIG_V8=v0.1.33
+ARG ZIG_V8=v0.1.35
 ARG TARGETPLATFORM
 
 RUN apt-get update -yq && \
@@ -40,9 +40,7 @@ WORKDIR /browser
 RUN git submodule init && \
     git submodule update --recursive
 
-RUN make install-libiconv && \
-    make install-netsurf && \
-    make install-mimalloc
+RUN zig build -Doptimize=ReleaseFast html5ever
 
 # download and install v8
 RUN case $TARGETPLATFORM in \
diff --git a/README.md b/README.md
index 87c393a5..5e25926a 100644
--- a/README.md
+++ b/README.md
@@ -140,13 +140,14 @@ You may still encounter errors or crashes. Please open an issue with specifics i
 
 Here are the key features we have implemented:
 
-- [x] HTTP loader (based on Libcurl)
-- [x] HTML parser and DOM tree (based on Netsurf libs)
-- [x] Javascript support (v8)
+- [x] HTTP loader ([Libcurl](https://curl.se/libcurl/))
+- [x] HTML parser ([html5ever](https://github.com/servo/html5ever))
+- [x] DOM tree
+- [x] Javascript support ([v8](https://v8.dev/))
 - [x] DOM APIs
 - [x] Ajax
   - [x] XHR API
-  - [x] Fetch API (polyfill)
+  - [x] Fetch API
 - [x] DOM dump
 - [x] CDP/websockets server
 - [x] Click
@@ -214,37 +215,15 @@ To init or update the submodules in the `vendor/` directory:
 make install-submodule
 ```
 
-**iconv**
+**html5ever**
 
-libiconv is an internationalization library used by Netsurf.
+[html5ver](https://github.com/servo/html5ever) is high-performance browser-grade HTML5 parser.
 
 ```
-make install-libiconv
+zig build html5ever
 ```
 
-**Netsurf libs**
-
-Netsurf libs are used for HTML parsing and DOM tree generation.
-
-```
-make install-netsurf
-```
-
-For dev env, use `make install-netsurf-dev`.
-
-**Mimalloc**
-
-Mimalloc is used as a C memory allocator.
-
-```
-make install-mimalloc
-```
-
-For dev env, use `make install-mimalloc-dev`.
-
-Note: when Mimalloc is built in dev mode, you can dump memory stats with the
-env var `MIMALLOC_SHOW_STATS=1`. See
-[https://microsoft.github.io/mimalloc/environment.html](https://microsoft.github.io/mimalloc/environment.html).
+For a release build, use `zig build -Doptimize=ReleaseFast html5ever`.
 
 **v8**
 
diff --git a/src/browser/js/bridge.zig b/src/browser/js/bridge.zig
index 73b588a1..026ccffa 100644
--- a/src/browser/js/bridge.zig
+++ b/src/browser/js/bridge.zig
@@ -493,7 +493,7 @@ pub const JsApis = flattenTypes(&.{
     @import("../webapi/collections.zig"),
     @import("../webapi/Console.zig"),
     @import("../webapi/Crypto.zig"),
-    @import("../webapi/CSS.zig"),
+    @import("../webapi/css.zig"),
     @import("../webapi/css/CSSRule.zig"),
     @import("../webapi/css/CSSRuleList.zig"),
     @import("../webapi/css/CSSStyleDeclaration.zig"),
diff --git a/src/browser/webapi/Element.zig b/src/browser/webapi/Element.zig
index 595d25fd..8836770a 100644
--- a/src/browser/webapi/Element.zig
+++ b/src/browser/webapi/Element.zig
@@ -32,7 +32,7 @@ pub const Attribute = @import("element/Attribute.zig");
 const CSSStyleProperties = @import("css/CSSStyleProperties.zig");
 pub const DOMStringMap = @import("element/DOMStringMap.zig");
 const DOMRect = @import("DOMRect.zig");
-const CSS = @import("CSS.zig");
+const CSS = @import("css.zig");
 const ShadowRoot = @import("ShadowRoot.zig");
 
 pub const Svg = @import("element/Svg.zig");
diff --git a/src/browser/webapi/Window.zig b/src/browser/webapi/Window.zig
index 84fae9f8..67093579 100644
--- a/src/browser/webapi/Window.zig
+++ b/src/browser/webapi/Window.zig
@@ -25,7 +25,7 @@ const Page = @import("../Page.zig");
 const Console = @import("Console.zig");
 const History = @import("History.zig");
 const Crypto = @import("Crypto.zig");
-const CSS = @import("CSS.zig");
+const CSS = @import("css.zig");
 const Navigator = @import("Navigator.zig");
 const Screen = @import("Screen.zig");
 const Performance = @import("Performance.zig");