# Open Source MMORPG Tools Updated October 11, 2026 A curated directory of open source tools for MMORPG players: boss practice overlays, DPS simulators, build editors, gear optimizers, XP trackers, and addon managers. Every entry is verified: a public repository, an OSI-approved license, an active or working project, and a live demo or download where one exists. ## How this directory was built We searched GitHub and the web for open source MMORPG tools, then verified each one by reading its repository and license file. Only tools with a verifiable open source license are listed; projects with missing or unclear licenses were left out. This page complements our own [MMORPG hub](/mmorpg/), which hosts our browser-based boss practice sims and calculators. Where a community tool pairs well with one of ours, we cross-link it instead of duplicating it. ### World of Warcraft - **Frostsim** GPL-3.0 Browser-only SimulationCraft compiled to WebAssembly. Run quick sims, gear comparisons, Top Gear searches, crest spending plans, and droptimizer runs entirely on your own machine: no queue, no account, nothing uploaded. *For raiders who want Raidbots-style gear sims without queues or logins.* [Repository](https://github.com/frostdev-ops/frostsim) - **SimulationCraft** GPL-3.0 The original event-driven WoW combat simulator that models player DPS across raid and dungeon scenarios, with detailed charts and stat-weight reports. The engine behind most community sim tools. *For theorycrafters who want the reference engine and full report detail.* [Repository](https://github.com/simulationcraft/simc) · [Downloads](https://www.simulationcraft.org) **Pairs well with our:** [WoW Time to Level Calculator](/wow-time-to-level-calculator/) ### Final Fantasy XIV - **cactbot** Apache-2.0 ACT overlay suite for FFXIV: raidboss timelines with text and audio callouts, mistake and death reporting, condensed job gauges, an Eureka/Bozja tracker, and a hunt radar. *For PC raiders who want BigWigs-style timelines and callouts in FFXIV.* [Repository](https://github.com/OverlayPlugin/cactbot) **Pairs well with our:** [FFXIV Materia Melding Calculator](/ffxiv-materia-melding-calculator/), [Titan Extreme Practice](/titan-ex-boss-sim-game/) ### Old School RuneScape - **Wise Old Man** MIT Open source XP tracking, competitions, leaderboards, and achievement records for OSRS players and clans, synced from the public hiscores. *For clan leaders and grinders who want tracked XP competitions and records.* [Repository](https://github.com/wise-old-man/wise-old-man) · [Live demo](https://wiseoldman.net) - **RuneWise** MIT A native desktop companion with 30+ tools: skill calculators, a DPS calculator covering thousands of monsters, dry and pet calculators, boss guides, live Grand Exchange prices, and event trackers. *For players who want every OSRS calculator in one fast desktop app.* [Repository](https://github.com/McNerve/runewise) - **OSRS Hours to Max** MIT Enter your username, pull your live hiscores, set XP rates per skill, and see exactly how many hours stand between you and a maxed account, with shareable result cards. *For anyone chasing the max cape who wants the honest hour count.* [Repository](https://github.com/davidcjw/osrs-hours-to-max) · [Live demo](https://hourstomax.davidcjw.com) - **osrs-dps-calc** GPL-3.0 The web DPS calculator behind the OSRS Wiki: compare loadouts by max hit, hit chance, attack speed, DPS, and time-to-kill against any monster. *For bossers optimizing gear setups before an expensive trip.* [Repository](https://github.com/weirdgloop/osrs-dps-calc) · [Live demo](https://tools.runescape.wiki) **Pairs well with our:** [OSRS XP Calculator](/osrs-xp-calculator/), [OSRS Drop Rate Calculator](/osrs-drop-rate-calculator/), [OSRS GP per Hour Calculator](/osrs-gp-per-hour-calculator/), [Zulrah Practice](/zulrah-boss-sim-game/) ### Guild Wars 2 - **Discretize Gear Optimizer** GPL-3.0 Finds the strongest PvE equipment setups for Guild Wars 2 builds: optimize for damage, effective health, or healing under constraints like boon duration and toughness. *For fractal and raid players squeezing the last percent out of their gear.* [Repository](https://github.com/discretize/discretize-gear-optimizer) · [Live demo](https://optimizer.discretize.eu) - **GW2 Build Optimizer** MIT An in-game Nexus addon that builds, improves, and explains character builds for PvE, PvP, and WvW, measured by a built-in combat simulator, with an AI chat assistant for build requests. *For Nexus users who want a build coach inside the game.* [Repository](https://github.com/special-place-ai-heaven/gw2_build_optimizer) - **gw2efficiency Build Editor (fork)** MIT An online build editor for Guild Wars 2 that uses the official API to keep skills, traits, and gear data up to date. *For players drafting and sharing builds in the browser.* [Repository](https://github.com/ieichen137/gw2builds) **Pairs well with our:** [GW2 Crafting Profit Calculator](/gw2-crafting-profit-calculator/) ### The Elder Scrolls Online - **ESO Addon Manager** MIT Cross-platform, open source addon manager for ESO (Linux, macOS, Windows, and Steam Deck via Flathub): install, update, and search addons from esoui.com without Java. *For ESO players who want Minion-style addon management without Java.* [Repository](https://github.com/arviceblot/eso-addons) **Pairs well with our:** [ESO Champion Points Calculator](/eso-champion-points-calculator/) ### Lost Ark - **Honing Forecast** AGPL-3.0 A browser honing calculator for Lost Ark: expected taps, material costs, and gold needed to reach your honing target. *For Lost Ark players planning honing sessions without blowing the gold stash.* [Repository](https://github.com/Kenivia/Honing-Forecast) · [Live demo](https://honing-forecast.pages.dev) **Pairs well with our:** [Lost Ark Honing Calculator](/lost-ark-honing-calculator/), [Valtan Gate 2 Practice](/valtan-gate-2-boss-sim-game/) ### Black Desert Online No verified open source tools found yet for Black Desert Online. In the meantime, try our own: **Pairs well with our:** [BDO Enhancement Calculator](/bdo-enhancement-calculator/) ### New World No verified open source tools found yet for New World. In the meantime, try our own: **Pairs well with our:** [New World Crafting Calculator](/new-world-crafting-calculator/) ## Frequently asked questions ### What counts as open source in this directory? Every entry links a public repository whose license file we read and verified: MIT, Apache-2.0, GPL-3.0, or AGPL-3.0, all OSI-approved. Projects with no license file or an unclear license are not listed, no matter how popular they are. ### Are these tools official? No. They are community and fan projects. They are not affiliated with or endorsed by Blizzard, Square Enix, Jagex, ArenaNet, ZeniMax, Smilegate, Pearl Abyss, or Amazon Games. ### Are they free to use? The source code is free and open. Browser tools run instantly with no account; desktop tools publish free installers on their releases pages. Some, like the GW2 in-game addon, need the game's own addon framework to run. ### How is this different from the /mmorpg/ hub? The /mmorpg/ hub hosts our own browser-based boss practice sims and calculators. This directory curates the best community-made open source tools. Where a community tool complements one of ours, we cross-link it instead of duplicating it. ### Why is a tool I like missing? We only list repositories we could verify: reachable, carrying an OSI-approved license, and maintained or functional. Several good-looking projects were skipped because they had no license file. If your favorite is missing, ask its maintainer to add a license.