Show HN: WebBase-III – dBASE III rebuilt in the browser with its own interpreter

WebBase-III, a browser-based reimplementation of the dBASE III database system, has been released as an open-source project. The tool includes a full W3Script interpreter, BROWSE grid, form engine, indexing, and multi-user support, all built with TypeScript, Node.js, WebSockets, and SQLite. It allows users to run classic dBASE commands and programs directly in a web browser without installation.

dBASE III is back. In your browser. USE customers like it's 1984. Remember the dot prompt? Before SQL won, before ORMs, before anyone said "full-stack" — there was dBASE III. You typed USE customers , then LIST , and your data was just there . WebBase-III brings that whole world back: the terminal, the language, BROWSE , @ SAY GET forms, .prg programs, indexes, reports — rebuilt from scratch as a modern web app with its own interpreter in TypeScript, backed by Node.js, WebSockets, and SQLite. Try it in one click — no install: The Codespace installs dependencies and starts the dev server automatically. Open the forwarded port 5173 and you're at the dot prompt. The command interface — type W3Script and see results instantly. LIST prints all records in active index order. The status bar shows the active database and table. INDEX ON name TO BYNAME creates a SQLite index and activates it — subsequent LIST output is sorted alphabetically. SEEK "Delta NV" jumps the record pointer to the first match in O log n . BROWSE opens a spreadsheet-style grid. Records are shown in active index order. Tab/Enter to edit a cell, Ctrl+N for a new row, Delete to remove a row, Esc to return to the terminal. EDIT <name opens the built-in .prg source editor. Programs support the full W3Script language: DO CASE/ENDCASE , DO WHILE/ENDDO , IF/ENDIF , form layouts, and all data commands. Ctrl+S saves, Esc cancels. @ row,col SAY "label" GET variable lays out character-cell form fields. READ renders them as a live form and waits for the user to fill in values and submit. The permanent left sidebar with category pickers and action buttons. Wizards open in the main area with a live W3Script preview. | Feature | Details | |---|---| W3Script interpreter | dBASE III command dialect: navigation, filters, variables, loops, conditionals, forms, programs | BROWSE grid | Inline cell editing, keyboard nav, index-ordered display | Form engine | @ ROW,COL SAY … GET character-cell layout with READ | Indexing | INDEX ON , SEEK , FIND — active index controls all record order | DO CASE | Multi-branch conditional, OTHERWISE fallback | Built-in functions | EOF , BOF , FOUND , RECNO , SUBSTR , STR , AT , CTOD , DTOC and more | Program files | Save, edit, and run .prg scripts with DO / EDIT | The Assistant | Permanent left sidebar — open databases/tables, browse, filter, index, search, design reports, run programs without typing | Multi-user | Each WebSocket connection gets its own isolated interpreter session | Persistent storage | better-sqlite3 with WAL mode — databases survive server restart | The sidebar on the left drives everything without typing: open or create databases and tables, browse and filter data, build indexes, search, design and run reports, and run programs. Every click generates a real W3Script command that echoes into the terminal — watch it to learn the language. Wizards New table, Filter, report designer, … open in the main area and show a live preview of the command they will run. npm install npm run dev http://localhost:5173 Production: npm run serve builds, then serves everything on http://localhost:3000 LAN / Tailscale: the server binds to 0.0.0.0 , so http://<tailscale-ip :3000 works out of the box. USE DATABASE mydb CREATE TABLE customers name CHAR 40 , phone CHAR 20 , country CHAR 30 USE customers APPEND RECORD REPLACE name WITH "Acme Corp", phone WITH "555-1234", country WITH "BE" APPEND RECORD REPLACE name WITH "Zeta Ltd", phone WITH "555-5678", country WITH "NL" INDEX ON name TO BYNAME LIST sorted A→Z SEEK "Zeta Ltd" jump to record instantly BROWSE open editable grid SET FILTER TO country == "BE" LIST filtered view SET FILTER TO clear filter WebBase-III supports unlimited work areas — each independently holding a table, record pointer, filter, and index. Link areas by key field using SET RELATION TO for relational data access. Cross-area field access uses alias.field dot notation. Note:dBASE III supported a maximum of 10 work areas DOS file handle limit . WebBase-III has no such limit. dBASE III used alias- field arrow syntax; WebBase-III uses modern alias.field dot notation. | Command | What it does | |---|---| SELECT <alias | Activate or create a work area by name | USE <table ALIAS <name | Open table in active area; optional alias override | SET RELATION TO <expr INTO <alias | Link active area to another; auto-seeks on every navigation | SET RELATION TO | Clear relation on active area | LIST col, alias.col, ... | List records; optional column list with cross-area fields | LIST AREAS | Show all open work areas, pointers, indexes, and relations | CLOSE | Close active area's table | CLOSE ALL | Close all work areas, reset to single empty area 1 | Cross-area field access : use alias.field dot notation anywhere an expression is accepted — SET FILTER TO , IF , REPLACE , LIST , INDEX ON . | Command | What it does | |---|---| USE <table | Select a table; restores any saved active index | USE DATABASE <name | Open a named SQLite database | LIST | Print records in active index order up to 500 | LIST STRUCTURE | Show column schema | LIST TABLES | Show all tables with record counts | LIST DATABASES | Show all databases on disk alias: LIST DBS | BROWSE | Open the editable grid | CLEAR | Clear terminal output | CREATE TABLE <n col TYPE, ... | Create a table | DROP TABLE <name | Delete a table | APPEND RECORD | Insert a blank row | DELETE / DELETE ALL | Delete current or all records | PACK | VACUUM the SQLite file | GO TOP / GO BOTTOM / GO <n | Move record pointer | SKIP <n | Move pointer forward/back | REPLACE <field WITH <val , ... | Update field s on current row | REPLACE ALL <field WITH <val , ... | Update all filtered rows | SET FILTER TO <expr | Set a WHERE clause; empty clears it | | Command | What it does | |---|---| INDEX ON <expr TO <tag | Create index on expression; sets it active immediately | SET INDEX TO <tag | Activate a previously created index | SET INDEX TO | Clear active index — restores natural insert order | REINDEX | Rebuild SQLite indexes for current table | LIST INDEXES | Print all indexes for current table with active marker | SEEK <expr | Position record pointer at first index match | FIND <string | Alias for SEEK unquoted string — dBASE III legacy form | | Command | What it does | |---|---| CREATE REPORT <name | Create a new report definition opens JSON editor | MODIFY REPORT <name | Edit an existing report definition | REPORT FORM <name | Run report — ASCII to terminal + HTML preview panel | LIST REPORTS | List all saved report definitions | DELETE REPORT <name | Delete a report definition | | Command | What it does | |---|---| DO <name | Run a saved .prg program | EDIT <name | Open .prg source editor | LIST PROGRAMS | Show all saved programs | Demo programs live in demos/ .prg and are the single source of truth: they are seeded into the program store on every server start, overwriting any store copy. Try DO inventory for a full interactive showcase work areas, relations, indexes, forms . | Command | What it does | |---|---| STORE <val TO <var | Assign a variable | INPUT "prompt" TO <var | Collect keyboard input | @ r,c SAY "text" GET <var | Define a form field | READ | Display the form and wait for submit | | Command | What it does | |---|---| IF <cond … ENDIF | Conditional block | DO WHILE <cond … ENDDO | Loop | DO CASE … ENDCASE | Multi-branch conditional CASE , OTHERWISE | HELP | Print command reference | QUIT | Exit | Functions work anywhere an expression is accepted — IF , DO WHILE , STORE , REPLACE , INDEX ON , SET FILTER TO , etc. | Function | Returns | |---|---| EOF | True if record pointer is past last record | BOF | True if record pointer is before first record | FOUND | True if last SEEK / FIND matched | RECNO | Current record number | RECCOUNT | Total records in current table | UPPER str | Uppercase | LOWER str | Lowercase | TRIM str | Strip leading and trailing spaces | LTRIM str | Strip leading spaces only | SUBSTR str, start, len | Substring — 1-based; len optional to end | LEN str | String length | AT needle, haystack | 1-based position; 0 if not found case-sensitive | STR num, len, dec | Number to right-justified string; default len=10, dec=0 | VAL str | String to number; non-numeric → 0 | INT n | Truncate toward zero | ABS n | Absolute value | SPACE n | String of n spaces | REPLICATE str, n | Repeat string n times | DATE | Today as MM/DD/YY | DTOC date | Date to display string MM/DD/YY | CTOD str | Display string MM/DD/YY to ISO date | W3Script supports both styles: | Syntax | Value | |---|---| TRUE / FALSE | Boolean true/false | .T. / .TRUE. | Boolean true dBASE III style | .F. / .FALSE. | Boolean false dBASE III style | Boolean values display as .T. / .F. in output to match dBASE conventions. Logical operators are accepted in both styles too: NOT / .NOT. , AND / .AND. , OR / .OR. e.g. DO WHILE .NOT. EOF . | Key | Action | |---|---| | Arrow keys | Navigate cells | | Enter / F2 | Edit selected cell | | Tab / Shift+Tab | Move right / left | | Ctrl+N | New row | | Delete | Delete current row | | F5 | Refresh from DB | | Esc | Exit grid, return to terminal | server/ index.ts Node.js HTTP + WebSocket server port 3000 Session.ts Per-connection session: parses commands, drives Executor SessionManager.ts Tracks all active sessions ServerDatabaseBridge.ts IDatabaseBridge impl wrapping better-sqlite3 ProgramStore.ts .prg program storage in data/system.sqlite3 IndexStore.ts Index metadata + active index in data/system.sqlite3 src/ interpreter/ Lexer.ts Tokenises W3Script input case-insensitive Parser.ts Recursive-descent AST builder Executor.ts Async AST runner; manages db/table/filter/vars/rowPtr/activeIndex Builtins.ts Stateless built-in function implementations terminal/ Terminal.ts REPL UI — command history, multi-line block accumulation ui/ Grid.ts BROWSE spreadsheet — inline cell editing, keyboard nav FormLayout.ts @ SAY GET form engine — character-cell coordinates ProgramEditor.ts .prg source editor UI ws/ WsClient.ts Browser WebSocket client npm test unit + integration tests Vitest npx playwright test end-to-end browser tests requires dev server running The Playwright suite tests/integration.spec.ts , tests/crm.spec.ts drives a real browser against the running app and covers navigation, filters, indexing, programs, forms, and BROWSE. AGPL-3.0 — see LICENSE.md /DDecoene/WebBaseIII/blob/main/LICENSE.md . Why AGPL? WebBase-III is a toy, and the license keeps it that way: anyone can use it, fork it, and learn from it, but nobody can take it closed and sell it as a hosted service without giving their changes back. If you want to run it, hack it, or ship features from your dBASE memories — that's exactly what it's for.