It is said classics never die. RPG Maker XP, the first of the series to be legally translated for English, is one of the older RPG creation engines available, but it still has lots of utility even in the modern-day.

For example, RPG Maker XP is THE engine of choice for the hordes of Pokemon fan games one can find all over the internet. The Pokemon Essentials project (now defunct thanks to a Nintendo C&D) was the base used by XP developers to make strikingly accurate Pokemon fangames to the point you could barely tell you weren't playing the actual games. With this in mind, it's easy to see why this engine's age is no strike against its popularity.

Like all others in the series, RPG Maker XP is a top-down, 2d based RPG creation engine. It was the first to implement Ruby-based scripting support, and while done in a far cruder way than VX/VX Ace, is still capable of greatly extending the engine's limits. XP also holds the distinction of having several features built-in later makers removed, which are only available if players re-enabled them via custom scripting code.

Graphically, it's better than the previous RPG Maker engines, which had even cruder graphics, though its tileset style leans more towards a low-fantasy, somewhat realistic look. Later entries would be more colorful and with a bias for high and urban fantasy. The character sprites are also much taller in XP, leaning for a more realistic look. Later engines could implement the same but at the cost of foregoing the standard "chibi" or super-deformed stock art. Enemy battler art is a bit disappointing, however, as while some is quite good, some looks quite amateurish.

Sounds and music are MIDI-based, and while the stock sounds and music are perfectly acceptable for a fantasy-based game and sound quite good for MIDI synthesized tracks, the engine does have the option for even higher quality OGG or MP3.

Controls for the editor are keyboard and mouse-driven and are not at all complicated. Controls aren't nearly as nice in the stock engine, with the animation being somewhat stiffer than in most other RPG Maker programs, resulting in some walking controls that feel a bit stilted.

Stability is an interesting topic, as this engine supports several features that had the potential to bring the engine to its knees if optimized poorly. Tilesets could be of infinite size, which could drastically increase loading times. The engine allowed for multiple tile layers, which could make for much more map detail and allow multi-tiered movement, such as making a bridge on an upper map layer you could walk under on the lower one on the same map. They had support for "fog" overlays, like a shadowy tree canopy overlay for forested areas, which gave the illusion of added realism. Finally, some of the database limits for XP were quite high, which later makers cut down by a profound degree.

Many of the above mentioned features were cut or greatly constrained in later makers in the series, and the playable frames per second were incredibly low by default as a consequence of attempting to keep the engine frame rate smooth. While custom scripting could extend the engine further, the already wobbly stock engine could be made much more unstable if said scripting was poorly optimized. Stock stability is acceptable for both editor and games made with it by contrast, even if the frame rates felt constrained.

Morally, this is not all that terrible an engine by default. Violence is possible if the combat engine is used, though generally in the turn-based RPG-style way. The language is entirely up to the creator; games can be as clean or perverse as they wish it to be.

Sexual content is pretty low to nil with the stock assets. Even the enemy battler graphics are restrained in the stock graphics, though this is partially due to most of them having low quality and a cartoonish, even garish look. There is some magic circle (with a hexagram pattern) like imagery available in the tiles and animations, but this remains strictly optional for use. Since games can be as wholesome or depraved as the creator intends, any ethical considerations are entirely at their discretion in terms of displayed morals.

Overall, RPG Maker XP is fairly cheap and worth the price, if only as a "license" so it's assets can be used in other RPG Maker engines if you are so inclined. It's also quite worthwhile on its own if you want an engine with more creative capability than some of its successors if you can accept its flaws and cruder scripting support.