diff --git a/Cargo.lock b/Cargo.lock
index cbef3fb..c3bd07a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -65,6 +65,12 @@ version = "1.0.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "86fdf8605db99b54d3cd748a44c6d04df638eb5dafb219b135d0149bd0db01f6"
 
+[[package]]
+name = "argparse"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f8ebf5827e4ac4fd5946560e6a99776ea73b596d80898f357007317a7141e47"
+
 [[package]]
 name = "async-channel"
 version = "2.3.1"
@@ -158,7 +164,7 @@ checksum = "a27b8a3a6e1a44fa4c8baf1f653e4172e81486d4941f2237e20dc2d0cf4ddff1"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -246,7 +252,7 @@ checksum = "57d123550fa8d071b7255cb0cc04dc302baa6c8c4a79f55701552684d8399bce"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -276,6 +282,36 @@ version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8c3c1a368f70d6cf7302d78f8f7093da241fb8e8807c05cc9e51a125895a6d5b"
 
+[[package]]
+name = "bincode"
+version = "1.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1f45e9417d87227c7a56d22e471c6206462cba514c7590c09aff4cf6d1ddcad"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "bit-set"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0700ddab506f33b20a03b13996eccd309a48e5ff77d0d95926aa0210fb4e95f1"
+dependencies = [
+ "bit-vec",
+]
+
+[[package]]
+name = "bit-vec"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "349f9b6a179ed607305526ca489b34ad0a41aed5f7980fa90eb03160b69598fb"
+
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
 [[package]]
 name = "bitflags"
 version = "2.6.0"
@@ -409,6 +445,32 @@ version = "0.9.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2459377285ad874054d797f3ccebf984978aa39129f6eafde5cdc8315b612f8"
 
+[[package]]
+name = "const_format"
+version = "0.2.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "50c655d81ff1114fb0dcdea9225ea9f0cc712a6f8d189378e82bdf62a473a64b"
+dependencies = [
+ "const_format_proc_macros",
+]
+
+[[package]]
+name = "const_format_proc_macros"
+version = "0.2.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eff1a44b93f47b1bac19a27932f5c591e43d1ba357ee4f61526c8a25603f0eb1"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
+[[package]]
+name = "convert_case"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6245d59a3e82a7fc217c5828a6692dbc6dfb63a0c8c90495621f7b9d79704a0e"
+
 [[package]]
 name = "cookie"
 version = "0.18.1"
@@ -450,6 +512,15 @@ version = "2.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "19d374276b40fb8bbdee95aef7c7fa6b5316ec764510eb64b8dd0e2ed0d7e7f5"
 
+[[package]]
+name = "crc32fast"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a97769d94ddab943e4510d138150169a2758b5ef3eb191a9ee688de3e23ef7b3"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "crossbeam-deque"
 version = "0.8.5"
@@ -529,6 +600,30 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "derivative"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcc3dd5e9e9c0b295d6e1e4d811fb6f157d5ffd784b8d202fc62eac8035a770b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
+[[package]]
+name = "derive_more"
+version = "0.99.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f33878137e4dafd7fa914ad4e259e18a4e8e532b9617a2d0150262bf53abfce"
+dependencies = [
+ "convert_case",
+ "proc-macro2",
+ "quote",
+ "rustc_version",
+ "syn 2.0.77",
+]
+
 [[package]]
 name = "deunicode"
 version = "1.6.0"
@@ -553,6 +648,12 @@ version = "0.15.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1aaf95b3e5c8f23aa320147307562d361db0ae0d51242340f558153b4eb2439b"
 
+[[package]]
+name = "downcast-rs"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75b325c5dbd37f80359721ad39aca5a29fb04c89279657cffdda8736d0c0b9d2"
+
 [[package]]
 name = "either"
 version = "1.13.0"
@@ -562,6 +663,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "entities"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5320ae4c3782150d900b79807611a59a99fc9a1d61d686faafc24b93fc8d7ca"
+
 [[package]]
 name = "equivalent"
 version = "1.0.1"
@@ -610,12 +717,32 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "fancy-regex"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b95f7c0680e4142284cf8b22c14a476e87d61b004a3a0861872b32ef7ead40a2"
+dependencies = [
+ "bit-set",
+ "regex",
+]
+
 [[package]]
 name = "fastrand"
 version = "2.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e8c02a5121d4ea3eb16a80748c74f5549a5665e4c21333c6098f283870fbdea6"
 
+[[package]]
+name = "flate2"
+version = "1.0.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1b589b4dc103969ad3cf85c950899926ec64300a1a46d76c03a6072957036f0"
+dependencies = [
+ "crc32fast",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "flume"
 version = "0.11.0"
@@ -721,7 +848,7 @@ checksum = "87750cf4b7a4c0625b1529e4c543c2182106e4dedc60a2a6455e00d212c489ac"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -801,7 +928,7 @@ version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bf760ebf69878d9fd8f110c89703d90ce35095324d1f1edcb595c63945ee757"
 dependencies = [
- "bitflags",
+ "bitflags 2.6.0",
  "ignore",
  "walkdir",
 ]
@@ -895,6 +1022,15 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "html-escape"
+version = "0.2.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d1ad449764d627e22bfd7cd5e8868264fc9236e07c752972b4080cd351cb476"
+dependencies = [
+ "utf8-width",
+]
+
 [[package]]
 name = "http"
 version = "1.1.0"
@@ -1038,6 +1174,16 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "idna"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e14ddfc70884202db2244c223200c204c2bda1bc6e0998d11b5e024d657209e6"
+dependencies = [
+ "unicode-bidi",
+ "unicode-normalization",
+]
+
 [[package]]
 name = "idna"
 version = "0.5.0"
@@ -1144,6 +1290,21 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "linked-hash-map"
+version = "0.5.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0717cef1bc8b636c6e1c1bbdefc09e6322da8a9321966e8928ef80d20f7f770f"
+
+[[package]]
+name = "linkify"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1dfa36d52c581e9ec783a7ce2a5e0143da6237be5811a0b3153fedfdbe9f780"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.4.14"
@@ -1177,6 +1338,7 @@ dependencies = [
  "common",
  "dotenvy",
  "futures-util",
+ "markdown-it",
  "oauth2",
  "reqwest",
  "serde",
@@ -1190,6 +1352,29 @@ dependencies = [
  "tracing-subscriber",
 ]
 
+[[package]]
+name = "markdown-it"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f99c010929c8217b2dc0940954267a2e15a15f17cb309cd1f299e21933f84fac"
+dependencies = [
+ "argparse",
+ "const_format",
+ "derivative",
+ "derive_more",
+ "downcast-rs",
+ "entities",
+ "html-escape",
+ "linkify",
+ "mdurl",
+ "once_cell",
+ "readonly",
+ "regex",
+ "stacker",
+ "syntect",
+ "unicode-general-category",
+]
+
 [[package]]
 name = "matchers"
 version = "0.1.0"
@@ -1215,6 +1400,17 @@ dependencies = [
  "digest",
 ]
 
+[[package]]
+name = "mdurl"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5736ba45bbac8f7ccc99a897f88ce85e508a18baec973a040f2514e6cdbff0d2"
+dependencies = [
+ "idna 0.3.0",
+ "once_cell",
+ "regex",
+]
+
 [[package]]
 name = "memchr"
 version = "2.7.4"
@@ -1468,7 +1664,7 @@ dependencies = [
  "pest_meta",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -1537,7 +1733,7 @@ checksum = "2f38a4412a78282e09a2cf38d195ea5420d15ba0602cb375210efbc877243965"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -1590,6 +1786,19 @@ version = "0.3.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "953ec861398dccce10c670dfeaf3ec4911ca479e9c02154b3a215178c5f566f2"
 
+[[package]]
+name = "plist"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42cf17e9a1800f5f396bc67d193dc9411b59012a5876445ef450d449881e1016"
+dependencies = [
+ "base64",
+ "indexmap",
+ "quick-xml",
+ "serde",
+ "time",
+]
+
 [[package]]
 name = "polling"
 version = "3.7.3"
@@ -1629,6 +1838,24 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "psm"
+version = "0.1.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa37f80ca58604976033fae9515a8a2989fc13797d953f7c04fb8fa36a11f205"
+dependencies = [
+ "cc",
+]
+
+[[package]]
+name = "quick-xml"
+version = "0.32.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d3a6e5838b60e0e8fa7a43f22ade549a37d61f8bdbe636d0d7816191de969c2"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "quinn"
 version = "0.11.5"
@@ -1716,13 +1943,24 @@ dependencies = [
  "getrandom",
 ]
 
+[[package]]
+name = "readonly"
+version = "0.2.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a25d631e41bfb5fdcde1d4e2215f62f7f0afa3ff11e26563765bd6ea1d229aeb"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.77",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0884ad60e090bf1345b93da0a5de8923c93884cd03f40dfcfddd3b4bee661853"
 dependencies = [
- "bitflags",
+ "bitflags 2.6.0",
 ]
 
 [[package]]
@@ -1859,13 +2097,22 @@ version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "583034fd73374156e66797ed8e5b0d5690409c9226b22d87cb7f19821c05d152"
 
+[[package]]
+name = "rustc_version"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfcb3a22ef46e85b45de6ee7e79d063319ebb6594faafcf1c225ea92ab6e9b92"
+dependencies = [
+ "semver",
+]
+
 [[package]]
 name = "rustix"
 version = "0.38.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8acb788b847c24f28525660c4d7758620a7210875711f79e7f663cc152726811"
 dependencies = [
- "bitflags",
+ "bitflags 2.6.0",
  "errno",
  "libc",
  "linux-raw-sys",
@@ -1940,6 +2187,12 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
+[[package]]
+name = "semver"
+version = "1.0.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61697e0a1c7e512e84a621326239844a24d8207b4669b41bc18b32ea5cbf988b"
+
 [[package]]
 name = "serde"
 version = "1.0.210"
@@ -1966,7 +2219,7 @@ checksum = "243902eda00fad750862fc144cea25caca5e20d615af0a81bee94ca738f1df1f"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -2194,7 +2447,7 @@ dependencies = [
  "quote",
  "sqlx-core",
  "sqlx-macros-core",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -2217,7 +2470,7 @@ dependencies = [
  "sqlx-mysql",
  "sqlx-postgres",
  "sqlx-sqlite",
- "syn",
+ "syn 2.0.77",
  "tempfile",
  "tokio",
  "url",
@@ -2231,7 +2484,7 @@ checksum = "64bb4714269afa44aef2755150a0fc19d756fb580a67db8885608cf02f47d06a"
 dependencies = [
  "atoi",
  "base64",
- "bitflags",
+ "bitflags 2.6.0",
  "byteorder",
  "bytes",
  "crc",
@@ -2273,7 +2526,7 @@ checksum = "6fa91a732d854c5d7726349bb4bb879bb9478993ceb764247660aee25f67c2f8"
 dependencies = [
  "atoi",
  "base64",
- "bitflags",
+ "bitflags 2.6.0",
  "byteorder",
  "crc",
  "dotenvy",
@@ -2326,6 +2579,19 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "stacker"
+version = "0.1.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "799c883d55abdb5e98af1a7b3f23b9b6de8ecada0ecac058672d7635eb48ca7b"
+dependencies = [
+ "cc",
+ "cfg-if",
+ "libc",
+ "psm",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "stringprep"
 version = "0.1.5"
@@ -2343,6 +2609,17 @@ version = "2.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
+[[package]]
+name = "syn"
+version = "1.0.109"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.77"
@@ -2369,6 +2646,28 @@ dependencies = [
  "futures-core",
 ]
 
+[[package]]
+name = "syntect"
+version = "5.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "874dcfa363995604333cf947ae9f751ca3af4522c60886774c4963943b4746b1"
+dependencies = [
+ "bincode",
+ "bitflags 1.3.2",
+ "fancy-regex",
+ "flate2",
+ "fnv",
+ "once_cell",
+ "plist",
+ "regex-syntax 0.8.4",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "thiserror",
+ "walkdir",
+ "yaml-rust",
+]
+
 [[package]]
 name = "tempfile"
 version = "3.12.0"
@@ -2421,7 +2720,7 @@ checksum = "08904e7672f5eb876eaaf87e0ce17857500934f4981c4a0ab2b4aa98baac7fc3"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -2505,7 +2804,7 @@ checksum = "693d596312e88961bc67d7f1f97af8a70227d9f90c31bba5806eec004978d752"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -2597,7 +2896,7 @@ version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8437150ab6bbc8c5f0f519e3d5ed4aa883a83dd4cdd3d1b21f9482936046cb97"
 dependencies = [
- "bitflags",
+ "bitflags 2.6.0",
  "bytes",
  "futures-util",
  "http",
@@ -2699,7 +2998,7 @@ checksum = "34704c8d6ebcbc939824180af020566b01a7c01f80641264eba0999f6c2b6be7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
@@ -2824,6 +3123,12 @@ version = "0.3.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08f95100a766bf4f8f28f90d77e0a5461bbdb219042e7679bebe79004fed8d75"
 
+[[package]]
+name = "unicode-general-category"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2281c8c1d221438e373249e065ca4989c4c36952c211ff21a0ee91c44a3869e7"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.13"
@@ -2845,6 +3150,12 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "52ea75f83c0137a9b98608359a5f1af8144876eb67bcb1ce837368e906a9f524"
 
+[[package]]
+name = "unicode-xid"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"
+
 [[package]]
 name = "unicode_categories"
 version = "0.1.1"
@@ -2864,11 +3175,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "22784dbdf76fdde8af1aeda5622b546b422b6fc585325248a2bf9f5e41e94d6c"
 dependencies = [
  "form_urlencoded",
- "idna",
+ "idna 0.5.0",
  "percent-encoding",
  "serde",
 ]
 
+[[package]]
+name = "utf8-width"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86bd8d4e895da8537e5315b8254664e6b769c4ff3db18321b297a1e7004392e3"
+
 [[package]]
 name = "valuable"
 version = "0.1.0"
@@ -2940,7 +3257,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
  "wasm-bindgen-shared",
 ]
 
@@ -2974,7 +3291,7 @@ checksum = "afc340c74d9005395cf9dd098506f7f44e38f2b4a21c6aaacf9a105ea5e1e836"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
@@ -3232,6 +3549,15 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
+[[package]]
+name = "yaml-rust"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56c1936c4cc7a1c9ab21a1ebb602eb942ba868cbd44a99cb7cdc5892335e1c85"
+dependencies = [
+ "linked-hash-map",
+]
+
 [[package]]
 name = "zerocopy"
 version = "0.7.35"
@@ -3250,7 +3576,7 @@ checksum = "fa4f8080344d4671fb4e831a13ad1e68092748387dfc4f55e356242fae12ce3e"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.77",
 ]
 
 [[package]]
diff --git a/lang-runner/src/run.rs b/lang-runner/src/run.rs
index 483b46d..2eb02ad 100644
--- a/lang-runner/src/run.rs
+++ b/lang-runner/src/run.rs
@@ -171,7 +171,7 @@ async fn run_lang(
     }
 
     let data = serde_json::to_string(&RunnerInput { lang, code, judge })
-        .map_err(|e| RunProcessError::SerializationFailed(e))?;
+        .map_err(RunProcessError::SerializationFailed)?;
     stdin.write_all(data.as_bytes()).await?;
 
     let output = child.output().await?;
diff --git a/main-server/Cargo.toml b/main-server/Cargo.toml
index d3da905..e5de5b9 100644
--- a/main-server/Cargo.toml
+++ b/main-server/Cargo.toml
@@ -22,3 +22,4 @@ oauth2 = "5.0.0-rc.1"
 tower-sessions = "0.13.0"
 tower-http = { version = "0.6.1", features = ["catch-panic", "fs"] }
 serde_json = "1.0.128"
+markdown-it = "0.6.1"
diff --git a/main-server/src/auto_output_format.rs b/main-server/src/auto_output_format.rs
index c91eaa1..7e2b823 100644
--- a/main-server/src/auto_output_format.rs
+++ b/main-server/src/auto_output_format.rs
@@ -18,7 +18,10 @@ use serde::Deserialize;
 use serde::{de::DeserializeOwned, Serialize};
 use tera::{escape_html, to_value, Context, Tera, Value};
 
-use crate::models::account::Account;
+use crate::{
+    markdown::MarkdownFilter,
+    models::account::Account,
+};
 
 #[derive(Serialize)]
 pub struct HtmlContext {
@@ -214,6 +217,7 @@ impl<T: Serialize> AutoOutputFormat<T> {
                 tera.autoescape_on(vec![".html.jinja", ".xml.jinja", ".html", ".xml"]);
                 tera.register_function("languages", get_langs);
                 tera.register_function("modules", load_assets);
+                tera.register_filter("markdown", MarkdownFilter);
                 tera
             })
         });
diff --git a/main-server/src/controllers/challenges.rs b/main-server/src/controllers/challenges.rs
index 1462df4..929b8f8 100644
--- a/main-server/src/controllers/challenges.rs
+++ b/main-server/src/controllers/challenges.rs
@@ -101,7 +101,7 @@ pub async fn new_challenge(
             )
                 .fetch_one(&pool)
                 .await
-                .map_err(|e| Error::DatabaseError(e))?;
+                .map_err(Error::DatabaseError)?;
 
             Ok(Redirect::temporary(&format!("/challenge/{row}")).into_response())
         }
diff --git a/main-server/src/main.rs b/main-server/src/main.rs
index 2deca1b..378f44d 100644
--- a/main-server/src/main.rs
+++ b/main-server/src/main.rs
@@ -2,6 +2,7 @@ mod auto_output_format;
 mod controllers;
 mod error;
 mod file_session_storage;
+mod markdown;
 mod models;
 mod session;
 mod test_solution;
diff --git a/main-server/src/markdown.rs b/main-server/src/markdown.rs
new file mode 100644
index 0000000..f397e82
--- /dev/null
+++ b/main-server/src/markdown.rs
@@ -0,0 +1,51 @@
+use std::cell::OnceCell;
+
+use markdown_it::{plugins::cmark::inline::link::Link, MarkdownIt};
+use tera::Filter;
+
+thread_local! {
+    static MARKDOWN: OnceCell<MarkdownIt> = const { OnceCell::new() };
+}
+
+pub fn render_markdown(source: &str) -> String {
+    MARKDOWN.with(|markdown| {
+        let parser = markdown.get_or_init(|| {
+            let mut parser = markdown_it::MarkdownIt::new();
+            markdown_it::plugins::cmark::add(&mut parser);
+            markdown_it::plugins::extra::add(&mut parser);
+            parser
+        });
+
+        let mut ast = parser.parse(source);
+
+        // TODO: this is probbly better with a plugin
+        ast.walk_mut(|e, _index| {
+            if e.is::<Link>() {
+                e.attrs.push(("rel", "nofollow noopener".to_owned()));
+            }
+        });
+        ast.render()
+    })
+}
+
+pub struct MarkdownFilter;
+
+impl Filter for MarkdownFilter {
+    fn is_safe(&self) -> bool {
+        true
+    }
+
+    fn filter(
+        &self,
+        value: &tera::Value,
+        args: &std::collections::HashMap<String, tera::Value>,
+    ) -> tera::Result<tera::Value> {
+        if !args.is_empty() {
+            return Err(tera::Error::msg("The markdown function takes no arguments"));
+        }
+        let text = value
+            .as_str()
+            .ok_or_else(|| tera::Error::msg("Expected type to be a string"))?;
+        Ok(tera::Value::String(render_markdown(text)))
+    }
+}
diff --git a/main-server/src/models/challenge.rs b/main-server/src/models/challenge.rs
index 14f5aa4..451fd93 100644
--- a/main-server/src/models/challenge.rs
+++ b/main-server/src/models/challenge.rs
@@ -56,7 +56,7 @@ impl ChallengeWithAuthorInfo {
             .bind(id)
             .fetch_optional(pool)
             .await
-            .map_err(|e| Error::DatabaseError(e))?;
+            .map_err(Error::DatabaseError)?;
 
         Ok(challenge)
     }
diff --git a/templates/base/base.html.jinja b/templates/base/base.html.jinja
index a378fc2..df25c1a 100644
--- a/templates/base/base.html.jinja
+++ b/templates/base/base.html.jinja
@@ -7,6 +7,7 @@
       <meta name="description" value="Yet Another Golf Site" />
       <meta name="keywords" value="code-golf" />
       <meta name="viewport" content="width=device-width, initial-scale=1" />
+      <meta charset="UTF-8" />
     {% endblock head %}
 
     {% block scripts %}
diff --git a/templates/challenge.html.jinja b/templates/challenge.html.jinja
index d7b48b2..070adfb 100644
--- a/templates/challenge.html.jinja
+++ b/templates/challenge.html.jinja
@@ -5,14 +5,16 @@
   <h1>{{ object.challenge.challenge.name }}</h1>
   <p>
     A challenge by
-    <img src="{{ object.challenge.author_avatar }}&size=18" alt="{{ object.challenge.author_name }} avatar" height="18" />
+    <img src="{{ object.challenge.author_avatar }}&size=18"
+         alt="{{ object.challenge.author_name }} avatar"
+         height="18" />
     {{ object.challenge.author_name }}
     <a href="/challenge/{{ object.challenge.id }}">Edit</a>
   </p>
   <div class="two-column-descripion">
     <div>
       <h3>Descripion</h3>
-      {{ object.challenge.challenge.description }}
+      {{ object.challenge.challenge.description | markdown }}
     </div>
     <div class="leaderboard">
       <h3>Leaderboard</h3>