diff --git a/README.md b/README.md
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+# QuickPeep
+
+Small-scale 'artisanal web' search engine project, favouring quality over completeness.
+
+
+## Motivation
+
+Modern web search can be rubbish.
+It feels like I'm getting the same websites time and time again, and that I rarely manage to come across small, independent websites instead of content/SEO mills.
+
+Typical modern websites are rubbish. They bother you with adverts, annoying nagging pop-ups (often loaded with dark patterns), privacy-disregarding trackers and slow-loading content that relies on needless amounts of JavaScript to display plain rich text that has been possible with pure HTML for decades.
+
+QuickPeep aims to index good-quality websites, favouring small personal sites (such as blogs), whilst cutting out the rubbish.
+Websites that don't care about the reader's experience are not welcome; QuickPeep will detect pop-up nags, adverts and privacy issues in order to keep them away.
+
+As a separate issue, many websites decide to use CloudFlare to intercept their traffic.
+This is not in the spirit of the decentralised web; CloudFlare becomes a single party that, if compromised or dishonest, could exert a disproportional amount of power over users.
+One notable example of this is that they bombard privacy-seeking users on VPNs or Tor with needless CAPTCHAs, giving them a worse experience on a lot of the web.
+These websites will be detected so that they can be filtered out at will.
+
+QuickPeep will follow the trade-off of preferring not to provide any results rather than to provide results laced with rubbish.
+If you need to fall back to a conventional search engine, this will eventually be possible to do right within QuickPeep...
+
+
+## Features
+
+*Crossed-out things are aspirational and not yet implemented.*
+
+- ~~Shareable 'rakepacks', so that anyone can run their own search instance without needing to rake (crawl) themselves~~
+    - ~~Dense encoding to minimise disk space usage; compressed with Zstd?~~
+- Raking (crawling) support for
+    - HTML (including redirecting to Canonical URLs)
+        - ~~Language detection~~
+    - Redirects
+    - ~~Gemtext over Gemini~~
+    - RSS, Atom and JSON feeds
+    - XML Sitemaps
+- Detection of anti-features, with ability to block or downrate as desired:
+    - CloudFlare
+    - Adverts
+    - Nagging pop-ups
+    - Trackers
+- Article content extraction, to provide more weight to words found within the article content (based on a Rust version of Mozilla's *Readability* engine)
+- (Misc)
+    - ~~Use of the Public Suffix List~~
+    - ~~Tagging URL patterns; e.g. to mark documentation as 'old'.~~
+- ~~Page duplicate content detection (e.g. to detect `/` and `/index.html`, or non-HTTPS and HTTPS, or non-`www` and `www`...)~~
+- ~~Language detection for pages that don't have that metadata available.~~
+
+
+## Limitations
+
+- Only supports English (and English dialects) for now.
+    - Should hopefully be customisable later on, but even though I can speak some foreign languages, I don't know any communities to start with to seed non-English search.
+- Websites have to be manually allowed and tagged.
+    - It's otherwise difficult to know how to detect good-quality sites automatically, or to tag what they are.
+    - There may be ways to improve this; e.g. with machine learning techniques or crowdsourcing of data.
+- The search index needs to remain small enough to be usable on modest hardware, so there's no way we can hope to index everything.
+
+
+## Architecture
+
+*Not written yet.*
+
+
+## Development and Running
+
+*Not written yet.*
+
+
+### Helper scripts
+
+`scripts` contains some helper scripts, which you probably need to run before operating QuickPeep:
+
+- `get_cf_ips.sh`: fetches IP addresses ued for CloudFlare detection.
+- `get_adblock_filters.sh`: fetches adblock filters used to detect nags/adverts/trackers.
+
diff --git a/quickpeep_densedoc/src/lib.rs b/quickpeep_densedoc/src/lib.rs
index e405883..5ad9c27 100644
--- a/quickpeep_densedoc/src/lib.rs
+++ b/quickpeep_densedoc/src/lib.rs
@@ -21,6 +21,8 @@ impl DenseDocument {
 pub struct DenseHead {
     title: String,
     feed_urls: Vec<String>,
+    /// Language of the page. May be empty if not discovered.
+    language: String,
     /// URL to icon of the page. May be empty if none were discovered.
     icon: String,
 }