diff --git a/Cargo.toml b/Cargo.toml
index 8502bec..967355c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,7 +11,11 @@ categories = [ "os::unix-apis" ]
 keywords = [ "freedesktop", "desktop", "entry" ]
 
 [dependencies]
+dirs = "5.0.1"
 gettext-rs = { version = "0.7", features = ["gettext-system"]}
 memchr = "2"
+textdistance = "1.0.2"
+strsim = "0.11.1"
 thiserror = "1"
 xdg = "2.4.0"
+log = "0.4.21"
diff --git a/src/decoder.rs b/src/decoder.rs
index 3c0c0ae..c255bfd 100644
--- a/src/decoder.rs
+++ b/src/decoder.rs
@@ -71,7 +71,10 @@ impl<'a> DesktopEntry<'a> {
     }
 
     /// Return an owned [`DesktopEntry`]
-    pub fn from_path<L>(path: PathBuf, locales_filter: Option<&[L]>) -> Result<DesktopEntry<'static>, DecodeError>
+    pub fn from_path<L>(
+        path: PathBuf,
+        locales_filter: Option<&[L]>,
+    ) -> Result<DesktopEntry<'static>, DecodeError>
     where
         L: AsRef<str>,
     {
@@ -125,7 +128,11 @@ fn process_line<'buf, 'local_ref, 'res: 'local_ref + 'buf, F, L>(
                 let locale = &key[start + 1..key.len() - 1];
 
                 match locales_filter {
-                    Some(locales_filter) if !locales_filter.iter().any(|l| l.as_ref() == locale) => return,
+                    Some(locales_filter)
+                        if !locales_filter.iter().any(|l| l.as_ref() == locale) =>
+                    {
+                        return
+                    }
                     _ => (),
                 }
 
diff --git a/src/lib.rs b/src/lib.rs
index eeea8b2..a1fcf12 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -4,6 +4,7 @@
 mod decoder;
 mod iter;
 
+pub mod matching;
 pub use decoder::DecodeError;
 
 pub use self::iter::Iter;
diff --git a/src/matching.rs b/src/matching.rs
new file mode 100644
index 0000000..724178d
--- /dev/null
+++ b/src/matching.rs
@@ -0,0 +1,124 @@
+// Copyright 2021 System76 <info@system76.com>
+// SPDX-License-Identifier: MPL-2.0
+
+use crate::DesktopEntry;
+
+impl<'a> DesktopEntry<'a> {
+    /// The returned value is between 0.0 and 1.0 (higher value means more similar).
+    /// You can use the `additional_haystack_values` parameter to add relevant string that are not part of the desktop entry.
+    pub fn match_query<Q, L>(
+        &'a self,
+        query: Q,
+        locales: &'a [L],
+        additional_haystack_values: &'a [&'a str],
+    ) -> f64
+    where
+        Q: AsRef<str>,
+        L: AsRef<str>,
+    {
+        #[inline]
+        fn add_value(v: &mut Vec<String>, value: &str, is_multiple: bool) {
+            if is_multiple {
+                value.split(';').for_each(|e| v.push(e.to_lowercase()));
+            } else {
+                v.push(value.to_lowercase());
+            }
+        }
+
+        // (field name, is separated by ";")
+        let fields = [
+            ("Name", false),
+            ("GenericName", false),
+            ("Comment", false),
+            ("Categories", true),
+            ("Keywords", true),
+        ];
+
+        let mut normalized_values: Vec<String> = Vec::new();
+
+        normalized_values.extend(
+            additional_haystack_values
+                .iter()
+                .map(|val| val.to_lowercase()),
+        );
+
+        let desktop_entry_group = self.groups.get("Desktop Entry");
+
+        for field in fields {
+            if let Some(group) = desktop_entry_group {
+                if let Some((default_value, locale_map)) = group.get(field.0) {
+                    add_value(&mut normalized_values, default_value, field.1);
+
+                    let mut at_least_one_locale = false;
+
+                    for locale in locales {
+                        match locale_map.get(locale.as_ref()) {
+                            Some(value) => {
+                                add_value(&mut normalized_values, value, field.1);
+                                at_least_one_locale = true;
+                            }
+                            None => {
+                                if let Some(pos) = locale.as_ref().find('_') {
+                                    if let Some(value) = locale_map.get(&locale.as_ref()[..pos]) {
+                                        add_value(&mut normalized_values, value, field.1);
+                                        at_least_one_locale = true;
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    if !at_least_one_locale {
+                        if let Some(domain) = &self.ubuntu_gettext_domain {
+                            let gettext_value = crate::dgettext(domain, default_value);
+                            if !gettext_value.is_empty() {
+                                add_value(&mut normalized_values, &gettext_value, false);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        let query = query.as_ref().to_lowercase();
+
+        let query_espaced = query.split_ascii_whitespace().collect::<Vec<_>>();
+
+        normalized_values
+            .into_iter()
+            .map(|de_field| {
+                let jaro_score = strsim::jaro_winkler(&query, &de_field);
+
+                if query_espaced.iter().any(|query| de_field.contains(*query)) {
+                    // provide a bonus if the query is contained in the de field
+                    (jaro_score + 0.1).clamp(0.61, 1.)
+                } else {
+                    jaro_score
+                }
+            })
+            .max_by(|e1, e2| e1.total_cmp(e2))
+            .unwrap_or(0.0)
+    }
+}
+
+/// Return the corresponding [`DesktopEntry`] that match the given appid.
+pub fn find_entry_from_appid<'a, I>(entries: I, appid: &str) -> Option<&'a DesktopEntry<'a>>
+where
+    I: Iterator<Item = &'a DesktopEntry<'a>>,
+{
+    let normalized_appid = appid.to_lowercase();
+
+    entries.into_iter().find(|e| {
+        if e.appid.to_lowercase() == normalized_appid {
+            return true;
+        }
+
+        if let Some(field) = e.startup_wm_class() {
+            if field.to_lowercase() == normalized_appid {
+                return true;
+            }
+        }
+
+        false
+    })
+}